def warshall_floyd(d):
    for k in range(N):
        for i in range(N):
            for j in range(N):
                d[i][j] = min(d[i][j], d[i][k]+d[k][j])
    
    return d

N, M, S, G = map(int, input().split())
d = [[10**18]*N for _ in range(N)]
adj_list = [[] for _ in range(N)]

for i in range(N):
    d[i][i] = 0

for _ in range(M):
    ai, bi, ci = map(int, input().split())
    d[ai][bi] = ci
    d[bi][ai] = ci
    adj_list[ai].append((bi, ci))
    adj_list[bi].append((ai, ci))

for i in range(N):
    adj_list[i].sort()

d = warshall_floyd(d)
ans = [S]

while True:
    prev = ans[-1]
    
    for nv, w in adj_list[prev]:
        if w+d[nv][G]==d[prev][G]:
            ans.append(nv)
            break
    
    if ans[-1]==G:
        break

print(*ans)