#include <iostream>

using namespace std;

int main()
{
	long long n, s;
	int m;

	cin >> n >> m >> s;
	s--;


	bool *occupied = new bool[n]();
	long long l, r;
	for (int i = 0; i < m; i++) {
		cin >> l >> r;
		l--;
		r--;
		for (long long y = l; y <= r; y++) {
			occupied[y] = true;
		}
	}

	long long p = -1;
	long long d = 1;


	while (p==-1) {
		if (s - d >= 0 && occupied[s - d] == false) {
			p = s - d;
		}
		else if (s + d < n && occupied[s+d]==false) {
			p = s + d;
		}
		d++;
	}

	p++;
	cout << p;

	delete[] occupied;

	return 0;
}