N = int(input())
M = int(input())

ans = N

ans_list = [0, 0, 0]
ans_list[N - 1] = 1

for i in range(M):
    change_info = [int(x) for x in input().split()]
    P = change_info[0] - 1
    Q = change_info[1] - 1
    
    tmp = ans_list[P]
    ans_list[P] = ans_list[Q]
    ans_list[Q] = tmp
    
print(ans_list.index(1) + 1)