n, m = list(map(int, input().split()))
A = []
C = [1]
Res = [1]
for i in range(m):
    A.append(list(map(int, input().split())))
s = 1
while len(Res) != n:
    for i in range(m):
        if A[i][0] == s:
            C.append(A[i][1])
        elif A[i][1] == s:
            C.append(A[i][0])
    C = list(set(C) - set(Res))
    s = min(C)
    Res.append(s)
print(*Res)