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

int main(){
    int n,m,p,q; cin >> n >> m;
    rep(i,0,m) {
        cin >> p >> q;
        if (q == n) n = p;
        if (p == n) n = q;
    }
    cout << n << endl;
}