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//fast
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;

#define all(x) x.begin(),x.end()
#define rep(n) for (int i = 0 ; i<n ; i++)
#define pb push_back

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
	ll n,m,s;
	cin >> n >> m >> s;
	pair<ll,ll> zaj[m+2];
	rep(m){
		cin >> zaj[i].first >> zaj[i].second;
	}
	zaj[m] = {0,0};
	zaj[m+1] = {n+1,n+1};
	m+=2;
	sort(zaj,zaj+m);
	int x;
	rep(m){
		if (zaj[i].first<=s && s<=zaj[i].second) x = i;
	}
	ll l = -1e16;
	ll r = 1e16;
	for (int i = x-1 ; i>=0 ; i--){
		if (zaj[i].second+1!=zaj[i+1].first){
			l = zaj[i+1].first-1;
			break;
		}
	}
	for (int i = x ; i<m-1 ; i++){
		if (zaj[i].second+1!=zaj[i+1].first){
			r = zaj[i].second+1;
			break;
		}
	}
	if (s-l<=r-s) cout << l << '\n';
	else cout << r << '\n';
}