#include <iostream>
#include <vector>
#include <queue>

using namespace std;


const int nmax=100000;
vector < int > g[nmax+1];
int viz[nmax+1],d[nmax+1];

void bfs(int x){
    queue < int > q;
    q.push(x);
    d[x]=0;
    viz[x]=1;
    while ( ! q.empty() ) {
        x=q.front();
        q.pop();
    }
    cout<<x; //pt parcurgere

    for (auto next : g[x]){
        if ( !viz[next] ){
            q.push(next);
            viz[next] = 1;
            d[next] = d[x] + 1;
        }
    }

}


int main() {

    int n,m, nod;
    cin>>n>>m>>nod;
    while (n--){
        int x,y ;
        cin>>x>>y;
        g[x].push_back(y);
    }

    bfs(nod);

    return 0;
}