/in/foo.cc: In function 'int dfs(int, int, int, int)':
/in/foo.cc:43:42: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(R char i=x;i<x+a1;i++) ch(a[i],a2,b,c,1);
                                          ^
/in/foo.cc:45:42: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(R char i=x;i<x+a1;i++) ch(a[i],a2,b,c,-1);
                                          ^
/in/foo.cc:50:42: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(R char i=x;i<x+b1;i++) ch(a[i],a2,b,c,1);
                                          ^
/in/foo.cc:52:42: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(R char i=x;i<x+a1;i++) ch(a[i],a2,b,c,-1);
                                          ^
/in/foo.cc:57:42: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(R char i=x;i<x+a1;i++) ch(a[i],a2,b,c,1);
                                          ^
/in/foo.cc:59:42: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(R char i=x;i<x+a1;i++) ch(a[i],a2,b,c,-1);
                                          ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:71:12: warning: array subscript has type 'char' [-Wchar-subscripts]
         a[i]=c-'A'+1;
            ^
/in/foo.cc:76:37: warning: array subscript has type 'char' [-Wchar-subscripts]
     for(R char i=1;i<=10;i++) nu[a[i]]++;
                                     ^