/in/foo.cc: In function 'long long int solve(long long int)':
/in/foo.cc:115:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < edge.size(); i ++) {
                 ~~^~~~~~~~~~~~~
/in/foo.cc: At global scope:
/in/foo.cc:140:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^