foo.cc: In function 'void ain()':
foo.cc:11:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   11 |         for(int i=0;i<s.size();i++){
      |                     ~^~~~~~~~~
foo.cc:12:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |                 for(int j=0;j<t.size();j++)
      |                             ~^~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务