import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())
M = int(readline())
m = map(int,read().split())
PQ = zip(m,m)

for p,q in PQ:
    if p == N:
        N = q
    elif q == N:
        N = p

print(N)