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

vector<pair<long long, long long>> P;

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	long long n, s;
	int m;
	cin >> n >> m >> s;
	
	for(int i=0; i<m; i++){
		long long a, b;
		cin >> a >> b;
		
		P.push_back({a, b});
	}
	
	sort(P.begin(), P.end());
	
	long long l=1, r=n;
	int k = 0;
	for(int i=0; i<P.size(); i++){
		if(P[i].first <= s && P[i].second >= s){
			k = i;
			l = P[i].first-1;
			r = P[i].second+1;
			break;
		}
	}
	
	for(int i=k-1; i>=0 && P[i].second >= l; i--){
		l = P[i].first-1;
	}
	for(int i=k+1; i<m && P[i].first <= r; i++){
		r = P[i].second+1;
	}
	
	if(l == 0){
		cout << r;
	}else if(r == n+1){
		cout << l;
	}else if(s-l <= r-s){
		cout << l;
	}else{
		cout << r;
	}

	

	return 0;
}