#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
    int N, M, P, Q;
    cin >> N >> M;
    for(int i = 1; i <= M; i++){
        cin >> P >> Q;
        swap(P, Q);
        if(N == Q){
            N = P;
        }
    }
    cout << N << endl; 
    return 0;
}