/in/foo.cc: In function 'int main()':
/in/foo.cc:15:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |                 for(int i=0;i<st.size();i++)
      |                             ~^~~~~~~~~~
/in/foo.cc:17:38: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   17 |                         if('a'<=st[i]&&st[i]<='z'||st[i]==' ')
      |                            ~~~~~~~~~~^~~~~~~~~~~~
/in/foo.cc:40:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |                         if(i==st.size()-1)
      |                            ~^~~~~~~~~~~~~