/in/foo.cc: In function 'int main()':
/in/foo.cc:24:28: error: 'x' was not declared in this scope
      if (mth(i)+mth(j)+mth(x)+4==n) ans++;
                            ^
/in/foo.cc:23:9: warning: unused variable 'z' [-Wunused-variable]
     int z=i+j;
         ^
/in/foo.cc:26:23: warning: format '%d' expects argument of type 'int', but argument 2 has type 'int*' [-Wformat=]
       printf("%d",&ans);
                       ^