foo.cc: In function 'int main()':
foo.cc:8:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |         for(int i=0;i<st.size();i++)
      |                     ~^~~~~~~~~~
foo.cc:10:18: error: 'class std::queue<char>' has no member named 'top'; did you mean 'pop'?
   10 |         q.push(q.top());
      |                  ^~~
      |                  pop
foo.cc:14:25: error: 'class std::queue<char>' has no member named 'top'; did you mean 'pop'?
   14 |                 cout<<q.top();
      |                         ^~~
      |                         pop

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