data/advent16a.txt

   1 Valve AA has flow rate=0; tunnels lead to valves DD, II, BB
   2 Valve BB has flow rate=13; tunnels lead to valves CC, AA
   3 Valve CC has flow rate=2; tunnels lead to valves DD, BB
   4 Valve DD has flow rate=20; tunnels lead to valves CC, AA, EE
   5 Valve EE has flow rate=3; tunnels lead to valves FF, DD
   6 Valve FF has flow rate=0; tunnels lead to valves EE, GG
   7 Valve GG has flow rate=0; tunnels lead to valves FF, HH
   8 Valve HH has flow rate=22; tunnel leads to valve GG
   9 Valve II has flow rate=0; tunnels lead to valves AA, JJ
  10 Valve JJ has flow rate=21; tunnel leads to valve II