/in/foo.cc: In function 'int main()':
/in/foo.cc:15:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while (s[i].size() < m + 3)
          ~~~~~~~~~~~~^~~~~~~
/in/foo.cc:33:9: error: expected unqualified-id before '[' token
    auto [x, y] = q.front();
         ^