#include <stdio.h>
#include <algorithm>
#include <deque>
using namespace std;
using ll = long long;

//26
int main() {
	int n, m, p, q;
	scanf("%d %d", &n, &m);
	for (int i = 0; i < m; i++) {
		scanf("%d %d", &p, &q);
		if (q == n)
			swap(p, q);
		if (p == n)
			n = q;
	}
	printf("%d\n", n);
}