/in/foo.cc: In function 'int bfs()':
/in/foo.cc:52:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i = 0; i < G[u].size(); i++)
                   ~~^~~~~~~~~~~~~
/in/foo.cc: In function 'LL dinic(int, LL)':
/in/foo.cc:67:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int &i = cur[u]; i < G[u].size(); i++)
                        ~~^~~~~~~~~~~~~
/in/foo.cc: In function 'void solve2()':
/in/foo.cc:151:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   LL mid = l + r >> 1;
            ~~^~~