#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef pair<int,int> P;
 
const int INF = 1e9;
const int mod = 1e9+7;
const double EPS = 1e-10;
const double PI = acos(-1.0);

int main()
{
    int n,m;
    cin >> n >> m;
    for(int i = 0; i < m; i++){
        int l,r;
        cin >> l >> r;
        if(n == l) n = r;
        else if(n == r) n = l;
    }
    cout << n << endl;
    return 0;
}