/in/foo.cc: In function 'int main()':
/in/foo.cc:53:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
/in/foo.cc:54:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  fo(i,1,n) fo(j,1,n) scanf("%d", &h[i][j]);
                                           ^