/in/foo.cc: In function 'int main()':
/in/foo.cc:31:38: error: no matching function for call to 'max(long long int)'
      f[i][j]=max(f[k][j-1]*nn[k][i-1]);
                                      ^
In file included from /usr/include/c++/6/bits/char_traits.h:39:0,
                 from /usr/include/c++/6/ios:40,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:2:
/usr/include/c++/6/bits/stl_algobase.h:219:5: note: candidate: template<class _Tp> const _Tp& std::max(const _Tp&, const _Tp&)
     max(const _Tp& __a, const _Tp& __b)
     ^~~
/usr/include/c++/6/bits/stl_algobase.h:219:5: note:   template argument deduction/substitution failed:
/in/foo.cc:31:38: note:   candidate expects 2 arguments, 1 provided
      f[i][j]=max(f[k][j-1]*nn[k][i-1]);
                                      ^
In file included from /usr/include/c++/6/bits/char_traits.h:39:0,
                 from /usr/include/c++/6/ios:40,
                 from /usr/include/c++/6/ostream:38,
                 from /usr/include/c++/6/iostream:39,
                 from /in/foo.cc:2:
/usr/include/c++/6/bits/stl_algobase.h:265:5: note: candidate: template<class _Tp, class _Compare> const _Tp& std::max(const _Tp&, const _Tp&, _Compare)
     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
     ^~~
/usr/include/c++/6/bits/stl_algobase.h:265:5: note:   template argument deduction/substitution failed:
/in/foo.cc:31:38: note:   candidate expects 3 arguments, 1 provided
      f[i][j]=max(f[k][j-1]*nn[k][i-1]);
                                      ^
In file included from /usr/include/c++/6/algorithm:62:0,
                 from /in/foo.cc:6:
/usr/include/c++/6/bits/stl_algo.h:3459:5: note: candidate: template<class _Tp> _Tp std::max(std::initializer_list<_Tp>)
     max(initializer_list<_Tp> __l)
     ^~~
/usr/include/c++/6/bits/stl_algo.h:3459:5: note:   template argument deduction/substitution failed:
/in/foo.cc:31:38: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
      f[i][j]=max(f[k][j-1]*nn[k][i-1]);
                                      ^
In file included from /usr/include/c++/6/algorithm:62:0,
                 from /in/foo.cc:6:
/usr/include/c++/6/bits/stl_algo.h:3465:5: note: candidate: template<class _Tp, class _Compare> _Tp std::max(std::initializer_list<_Tp>, _Compare)
     max(initializer_list<_Tp> __l, _Compare __comp)
     ^~~
/usr/include/c++/6/bits/stl_algo.h:3465:5: note:   template argument deduction/substitution failed:
/in/foo.cc:31:38: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
      f[i][j]=max(f[k][j-1]*nn[k][i-1]);
                                      ^