/in/foo.cc: In function 'void solve()':
/in/foo.cc:23:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < score.size(); ++i) {
                     ~~^~~~~~~~~~~~~~
/in/foo.cc:39:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < score.size(); ++i) {
                     ~~^~~~~~~~~~~~~~