cap = [None,None,None]
N = int(input())
M = int(input())
P = [input().split(' ') for i in range(M)]
cap[N-1] = 1
for i in P:
    tmp = cap[int(i[1])-1]
    cap[int(i[1])-1] = cap[int(i[0])-1]
    cap[int(i[0])-1] = tmp
print(cap.index(1)+1)