#include<iostream>

int main() {
    int N, M;
    std::cin >> N;
    std::cin >> M;

    int ans = N;
    for (int i = 0; i < M; ++i) {
        int p, q;
        std::cin >> p >> q;
        if (ans == p) {
            ans = q;
        } else if (ans == q) {
            ans = p;
        }
    }

    std::cout << ans;
}