1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define vc vector
#define st first
#define nd second
#define pll pair<ll, ll>
#define sz(a) (ll)a.size()
#define all(a) a.begin(), a.end()
#define pu push
#define pub push_back
#define pob pop_back
#define em emplace
#define emb emplace_back
const ll INF = 2e18;

void program() {
	ll n, m, s;
	cin >> n >> m >> s;
	vc<pll> a(m);
	for (pll &ai : a)
		cin >> ai.st >> ai.nd;
	
	sort(all(a));
	vc<pll> tmp = {a[0]};
	for (ll i = 1; i < m; i++) {
		if (tmp.back().nd + 1 == a[i].st)
			tmp.back().nd = a[i].nd;
		else
			tmp.pub(a[i]);
	}
	swap(tmp, a);

	ll l, r;
	for (pll &ai : a)
		if (ai.st <= s and s <= ai.nd) {
			l = ai.st;
			r = ai.nd;
		}

	if ((s - l <= r - s and l - 1 >= 1) or r + 1 > n)
		cout << l - 1 << "\n";
	else
		cout << r + 1 << "\n";
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	program();
	return 0;
}