foo.cc: In function 'int main()':
foo.cc:21:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:23:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         for (int j=0;j<m;++j) scanf("%d",&h[i][j]);
                               ~~~~~^~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务