/in/foo.cc: In function 'int read()':
/in/foo.cc:13:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   if(ch=='-')v=-1;ch=getchar();
   ^~
/in/foo.cc:13:19: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
   if(ch=='-')v=-1;ch=getchar();
                   ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:34:14: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
       if(i!=k&&j!=f||i==k&&k==n&&j==f&&f==m)
          ~~~~^~~~~~