N = int(input())
M = int(input())
PQ = [list(map(int, input().split(' '))) for _ in range(M)]

for i in range(M):
    if N == PQ[i][0]:
        N = PQ[i][1]
    elif N == PQ[i][1]:
        N = PQ[i][0]
    else:
        continue
    

print(N)