#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int n, m;
    cin >> n >> m;
    while (m--) {
        int p, q;
        cin >> p >> q;
        if (n == p) n = q;
        else if (n == q) n = p;
    }
    cout << n << endl;
    return 0;
}