/in/foo.cc: In function 'bool bfs()':
/in/foo.cc:35:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for( register int i = 0 ; i < linker[ now ].size() ; i++ )
                             ~~^~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'long long int dinic(int, long long int)':
/in/foo.cc:43:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for( register int i = cur[ now ] ; i < linker[ now ].size() ; i++ ) {
                                     ~~^~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc: In function 'bool check(long long int)':
/in/foo.cc:61:18: error: reference to 'hash' is ambiguous
     addedge( s , hash[i][j] , x - a[i][j] ) , tot += x - a[i][j];
                  ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:62:27: error: reference to 'hash' is ambiguous
     if( i != 1 ) addedge( hash[i][j] , hash[i - 1][j] , inf );
                           ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:62:40: error: reference to 'hash' is ambiguous
     if( i != 1 ) addedge( hash[i][j] , hash[i - 1][j] , inf );
                                        ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:63:27: error: reference to 'hash' is ambiguous
     if( i != n ) addedge( hash[i][j] , hash[i + 1][j] , inf );
                           ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:63:40: error: reference to 'hash' is ambiguous
     if( i != n ) addedge( hash[i][j] , hash[i + 1][j] , inf );
                                        ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:64:27: error: reference to 'hash' is ambiguous
     if( j != 1 ) addedge( hash[i][j] , hash[i][j - 1] , inf );
                           ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:64:40: error: reference to 'hash' is ambiguous
     if( j != 1 ) addedge( hash[i][j] , hash[i][j - 1] , inf );
                                        ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:65:27: error: reference to 'hash' is ambiguous
     if( j != m ) addedge( hash[i][j] , hash[i][j + 1] , inf );
                           ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.h:5643:0,
                 from /usr/include/c++/6/string:52,
                 from /usr/include/c++/6/bits/locale_classes.h:40,
                 from /usr/include/c++/6/bits/ios_base.h:41,
                 from /usr/include/c++/6/ios:42,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:1:
/usr/include/c++/6/bits/functional_hash.h:58:12: note:                 template<class _Tp> struct std::hash
     struct hash;
            ^~~~
/in/foo.cc:65:40: error: reference to 'hash' is ambiguous
     if( j != m ) addedge( hash[i][j] , hash[i][j + 1] , inf );
                                        ^~~~
/in/foo.cc:19:33: note: candidates are: int hash [42][42]
 int n , m , a[40 + 2][40 + 2] , hash[40 + 2][40 + 2] , r;
                                 ^~~~
In file included from /usr/include/c++/6/bits/basic_string.