mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline
    import heapq

    def dijkstra(adj, start):
        # adj: [[to, cost] * vertices], 0th index must be empty
        inf = 1 << 60
        dist = [inf] * len(adj)
        dist[start] = 0
        q = []
        heapq.heappush(q, (0, start))
        while q:
            min_dist, v_from = heapq.heappop(q)
            if min_dist > dist[v_from]:
                continue
            v_tos = adj[v_from]
            for v_to, cost in v_tos:
                if min_dist + cost < dist[v_to]:
                    dist[v_to] = min_dist + cost
                    heapq.heappush(q, (dist[v_to], v_to))
        return dist

    N, M = map(int, input().split())
    adj = [[] for _ in range(N * 1001 + 1)]
    ABC = []
    for _ in range(M):
        ABC.append(tuple(map(int, input().split())))
    T = [0] + list(map(int, input().split()))
    for a, b, c in ABC:
        ta = T[a]
        tb = T[b]
        for p in range(1001):
            if 0 < ta + p <= 1000:
                adj[a + N * p].append((b + N * (p + ta), c // (p + ta) + ta))
            if 0 < tb + p <= 1000:
                adj[b + N * p].append((a + N * (p + tb), c // (p + tb) + tb))
        adj[a + N * 1000].append((b + N * 1000, ta))
        adj[b + N * 1000].append((a + N * 1000, tb))
    dist = dijkstra(adj, 1)
    ans = float("inf")
    for p in range(1001):
        ans = min(ans, dist[N + N * p])
    print(ans)


if __name__ == '__main__':
    main()