/in/foo.cc: In function 'bool k(std::string)':
/in/foo.cc:7:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    7 |         for(int i=0;i<s.size();i++)
      |                     ~^~~~~~~~~
/in/foo.cc:20:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   20 |         if(d==0||s.size()<6||s.size()>12||e==1)
      |         ^~
/in/foo.cc:22:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   22 |                 if(a+b+c<2)
      |                 ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:29:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |         for(int i=0;i<s.size();i++)
      |                     ~^~~~~~~~~