foo.cc: In function 'int main()':
foo.cc:50:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |    for(int j=0;j<v[i].size();j++)
      |                ~^~~~~~~~~~~~
foo.cc:20:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   20 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:23:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |    scanf("%d",&t[i][j]);
      |    ~~~~~^~~~~~~~~~~~~~~

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