#include <iostream>

using namespace std;

int N, M;

int main() {
    cin >> N >> M;
    for (int i = 0; i < M; i++) {
        int P, Q;
        cin >> P >> Q;
        if (N == P) N = Q;
        else if (N == Q) N = P;
    }
    cout << N << endl;
    return 0;
}