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

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	
	ll n, m, s;
	cin >> n >> m >> s;
	vector<pair<ll, ll>> zabl(m);
	for(int i=0; i<m; ++i) cin >> zabl[i].first >> zabl[i].second;
	ll szkola = 0;
	sort(zabl.begin(), zabl.end());
	for(int i=0; i<m; ++i) if(s>=zabl[i].first && s<=zabl[i].second) szkola = i;
	ll left_first = -1;
	ll right_first = -1;
	ll idx = szkola;
	while(idx>0) {
		if(zabl[idx].first-1 != zabl[idx-1].second) {
			left_first = zabl[idx].first-1;
			break;
		}
		idx--;
	}
	if(idx==0 && left_first==-1 && zabl[0].first > 1) left_first = zabl[0].first-1;
	idx = szkola;
	while(idx<m-1) {
		if(zabl[idx].second+1 != zabl[idx+1].first) {
			right_first = zabl[idx].second+1;
			break;
		}
		idx++;
	}
	if(idx==m-1 && right_first==-1 && zabl[m-1].second < n) right_first = zabl[m-1].second+1;
	if(left_first == -1) left_first = right_first;
	if(right_first == -1) right_first = left_first;
	if(abs(s-left_first) <= abs(s-right_first)) cout << left_first << "\n";
	else cout << right_first << "\n";
	
	return 0;
}