1916. 최소비용 구하기

import sys


def register_bus(src, dst, cost):
    # TODO
    return


def solve(src, dst):
    # TODO
    return 0


if __name__ == "__main__":
    N = int(sys.stdin.readline())
    M = int(sys.stdin.readline())

    for _ in range(M):
        src, dst, cost = map(int, sys.stdin.readline().split())
        register_bus(src, dst, cost)

    src, dst = map(int, sys.stdin.readline().split())
    print(solve(src, dst))