#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <stack>
using namespace std;

#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
#define SQR(X) ((X)*(X))

typedef long long ll;
typedef unsigned long long ull;
typedef long double lb;
/* ここからが本編 */

int main(void)
{
   int i,j;
   int n,m;
   int p,q;
   cin >> n >> m;
   while(cin >> p >> q) {
      if(p == n) n = q;
      else if(q == n) n = p;
   }
   cout << n << endl;

   
   return 0;
}