def main():
    N = int(input())
    M = int(input())
    PQ = tuple(tuple(map(int, input().split())) for _ in [0] * M)

    cup = [0, 0, 0, 0]
    cup[N] = 1
    for p, q in PQ:
        cup[p], cup[q] = cup[q], cup[p]

    print(cup.index(1))

main()