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

P = [0] * M
Q = [0] * M

current = N

for i in range(M):
    P[i], Q[i] = map(int,input().split())

for i in range(M):
    if P[i] == current:
        current = Q[i]
    elif Q[i] == current:
        current = P[i]

print(current)