/in/foo.cc: In function 'int main()':
/in/foo.cc:7:8: warning: unused variable 'y' [-Wunused-variable]
  int x,y,i,j,k,n,m,f[100][100];
        ^
/in/foo.cc:7:14: warning: unused variable 'k' [-Wunused-variable]
  int x,y,i,j,k,n,m,f[100][100];
              ^
/in/foo.cc:8:7: warning: unused variable 't' [-Wunused-variable]
  char t[100],ch[100][100];
       ^