foo.cc: In function 'int main()':
foo.cc:9:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    9 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:11:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   11 |    for (int j=1;j<=m;j++) scanf("%d",&a[i][j]);
      |                           ~~~~~^~~~~~~~~~~~~~~

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