from collections import * N, M, S, G = map(int, input().split()) inf = 10 ** 18 dp = [[inf] * N for i in range(N)] for i in range(N): dp[i][i] = 0 Edge = defaultdict(lambda:inf) for i in range(M): a, b, c = map(int, input().split()) dp[a][b] = min(dp[a][b], c) dp[b][a] = min(dp[b][a], c) Edge[(a, b)] = min(Edge[(a, b)], c) Edge[(b, a)] = min(Edge[(b, a)], c) for k in range(N): for i in range(N): for j in range(N): dp[i][j] = min(dp[i][j], dp[i][k] + dp[k][j]) ans = [S] now = S cost = dp[now][G] while now != G: for i in range(N): if i == now: continue if dp[now][i] + dp[i][G] == cost and Edge[(now, i)] == dp[now][i]: ans.append(i) cost -= dp[now][i] now = i break print(*ans)