foo.cc: In function 'int main()':
foo.cc:12:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |         for(int i=0;i<v1.size();i++)
      |                     ~^~~~~~~~~~
foo.cc:13:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |                 for(int j=0;j<v2.size();j++)
      |                             ~^~~~~~~~~~
foo.cc:15:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for(int i=0;i<v3.size();i++)
      |                     ~^~~~~~~~~~
foo.cc:18:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |                         if(i==v3.size()-1)v3.push_back(0);
      |                            ~^~~~~~~~~~~~~

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