output_description: Print the shortest distance in a line. If there is no solution, print -1.
input_description: |V| |E|
      s0 t0 d0
      s1 t1 d1
      :
      s|E|-1 t|E|-1 d|E|-1
      
  
  |V| is the number of vertices and |E| is the number of edges in the graph. The
  graph vertices are named with the numbers 0, 1,..., |V|-1 respectively.
  
  si and ti represent source and target vertices of i-th edge (directed) and di
  represents the distance between si and ti (the i-th edge).
attempt: #!/usr/bin/env python3
  import sys
  from collections import defaultdict
  
  rl = sys.stdin.buffer.readline
  INF = sys.maxsize
  
  V, E = map(int, rl().split())
  ES = [tuple(map(int, rl().split())) for i in range(E)]
  
  
  # グラフを初期化する
  G = defaultdict(lambda: defaultdict(lambda: INF))
  for e in ES:
      G[e[0]][e[1]] = e[2]
  
  
  dp = defaultdict(lambda: defaultdict(lambda: INF))
  dp[0][0] = 0
  
  for s in range(1 << V):
      for v in range(V):
          if s & (1 << v) == 0:  # s に頂点v が含まれていないときを考える
              for u in range(V):
                  dp[s | (1 << v)][v] = min(dp[s | (1 << v)][v], dp[s][u] + G[u][v])
  
  
  print(dp[(1 << V) - 1][0] if dp[(1 << V) - 1][0] < INF else -1)
  
problem_description: Traveling Salesman Problem
  
    
  
  For a given weighted directed graph G(V, E), find the distance of the shortest
  route that meets the following criteria:
  
    * It is a closed cycle where it ends at the same point it starts.
    * It visits each vertex exactly once.
samples: [{"input": "4 6\n    0 1 2\n    1 2 3\n    1 3 9\n    2 0 1\n    2 3 6\n    3 2 4", "output": "16"}, {"input": "3 3\n    0 1 1\n    1 2 1\n    0 2 1", "output": "-1"}]