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
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
#include <bits/stdc++.h>
using namespace std;
#define fwd(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) fwd(i, 0, n)
#define all(X) X.begin(), X.end()
#define sz(X) int(size(X))
#define pb push_back
#define eb emplace_back
#define st first
#define nd second
using pii = pair<int, int>; using vi = vector<int>;
using ll = long long; using ld = long double;
#ifdef LOC
auto SS = signal(6, [](int) { *(int *)0 = 0; });
#define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; }
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { (( cerr << x << ", " ), ...) << '\n'; }
#define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define deb(...) 0
#endif

#define S 1007

ll L[S], R[S];

int32_t main() {
	cin.tie(0)->sync_with_stdio(0);
	cout << fixed << setprecision(10);

	ll n,s;
	int m;
	cin >> n >> m >> s;
	set<ll> sett;
	for(int i = 1; i <= m; i++) {
		cin >> L[i] >> R[i];
		sett.insert(L[i]-1);
		sett.insert(R[i]+1);
	}
	sett.insert(1);
	sett.insert(n);

	ll ans = 2e15;
	ll pos = -1;
	for(auto v: sett) {
		if(v < 1 || v > n)
			continue;
		bool good = true;
		for(int i =  1; i <= m; i++) {
			if(v >= L[i] && v <= R[i]) {
				good = false;
				break;
			}
		}
		if(good) {
			if(abs(v-s) < ans) {
				ans = abs(v-s);
				pos = v;
			} else if(abs(v-s) == ans) {
				pos = min(pos, v);
			}
		}
	}
	cout << pos << "\n";
}	

/*
10 2 7 
5 9
1 2

15 4 9
4 5
10 13
1 1 
6 9
*/