N=int(input())
M=int(input())
P = []
Q= []
for i in range(M):
    x1,y1=[int(i) for i in input().split()]
    P.append(x1)
    Q.append(y1)


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

print(now)