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

int main() {
//	ifstream cin("tests/0b.in");

	cin.tie(NULL);
	cout.tie(NULL);
	ios_base::sync_with_stdio(false);

	long long int n, s;
	int m;
	cin >> n;
	cin >> m;
	cin >> s;

	vector<pair<long long int, long long int>> ranges(m);
	for (int i = 0; i < m; i++) {
		cin >> ranges[i].first;
		cin >> ranges[i].second;
	}

	sort(ranges.begin(), ranges.end());

	int cs = 0;
	for (; cs < m; cs++) {
		pair<long long int, long long int> &p = ranges[cs];
		if (p.first <= s && p.second >= s) {
			break;
		}
	}
	long long int left = ranges[cs].first;
	long long int right = ranges[cs].second;
	if (cs > 0) {
		for (int li = cs - 1; li >= 0; li--) {
			if (ranges[li].second + 1 < left) {
				break;
			} else {
				left = ranges[li].first;
			}
		}
	}

	if (cs < m - 1) {
		for (int rj = cs + 1; rj < m; rj++) {
			if (right < ranges[rj].first - 1) {
				break;
			} else {
				right = ranges[rj].second;
			}
		}
	}

	long long int pos;
	long long int distance = n;
	if (right < n) {
		distance = right + 1 - s;
		pos = right + 1;
	}
	if (left > 1 && s - left + 1 <= distance) {
		pos = left - 1;
	}

	cout << pos << endl;

	return 0;
}