#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < n; i++)
using namespace std;

int n, m;

int main(){
	scanf("%d%d",&n,&m);
	rep(i,m){
		int a, b;
		scanf("%d%d", &a, &b);
		if(a == n) n = b;
		else if(b == n) n = a;
	}
	printf("%d\n", n);
}