class Problem0026:
    def solve(this):
        n = int(input())
        m = int(input())
        for i in range(m):
            p,q = map(int, input().split())
            if n == p:
                n = q
            elif n == q:
                n = p
        print(n)
		
if __name__ == "__main__":
    problem = Problem0026()
    problem.solve()