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// Author: Olaf Surgut (surgutti)
// Created on 11-03-2025 15:31:45
#include "bits/stdc++.h"
using namespace std;

#define int long long
#define ll long long
#define ld long double

#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define all(x) begin(x),end(x)
#define FOR(i,l,r) for(int i=(l);i<=(r);i++)
#define ROF(i,r,l) for(int i=(r);i>=(l);i--)

auto& operator<<(auto &o, pair<auto, auto> p) {
	return o << "(" << p.st << ", " << p.nd << ")";}
auto operator<<(auto &o, auto x)->decltype(end(x), o) {
	o << "{"; int i=0; for (auto e : x) o << ","+!i++ << e;
	return o << "}";}

#ifdef LOCAL
#define debug(x...) cerr << "[" #x "]: ", [](auto...$) { \
	((cerr << $ << "; "),...) << endl; }(x)
#else
#define debug(...)
#endif

#define rep(i,a,b) for(int i = a; i < (b); i++)
using pii = pair<int, int>;
using vi = vector<int>;

signed main() {
	cin.tie(0)->sync_with_stdio(0);
	
	int n, m, s;
	cin >> n >> m >> s;
	
	vector<pii> seg(m);
	for (auto& [l, r] : seg)
		cin >> l >> r;
	
	sort(all(seg));

	vector<pii> stk;
	for (auto [l, r] : seg) {
		debug(stk, l, r);
		while (sz(stk) > 0 && l <= stk.back().nd + 1) {
			l = min(l, stk.back().st);
			r = max(r, stk.back().nd);
			stk.pop_back();
		}

		stk.eb(l, r);
	}

	debug(stk);

	auto [l, r] = *prev(upper_bound(all(stk), make_pair(s + 1, s)));
	debug(l, r);
	l--, r++;

	if (l < 1)	l = r;
	if (r > n)	r = l;

	debug(l, r);

	if (abs(s - l) <= abs(s - r))
		cout << l << '\n';
	else
		cout << r << '\n';

	return 0;
}