import sys

sys.setrecursionlimit(10 ** 8)

input = sys.stdin.readline


def main():
    N = int(input())
    M = int(input())
    PQ = [[int(x) for x in input().split()] for _ in range(M)]

    for p, q in PQ:
        if p == N:
            N = q
        elif q == N:
            N = p

    print(N)


if __name__ == '__main__':
    main()