/in/foo.cc: In function 'int main()':
/in/foo.cc:10:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   10 |   for(long long int i=0;i<strlen(a);i++){
      |                         ~^~~~~~~~~~