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
#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 << ")"; }
auto operator<<(auto &o, auto a) -> decltype(all(a), o);
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
#define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", [](auto... arg_) { (( cerr << arg_ << ", " ), ...) << '\n'; }(x)
#else
#define deb(...) 0
#endif

void solve() {
    ll n, m, school;
    cin >> n >> m >> school;

    vector<pair<ll, ll>> seg(m);
    for (auto &[a, b] : seg) {
        cin >> a >> b;
    }
    sort(all(seg));
    ll ne = school + 1, pr = school - 1;

    for (auto [a, b] : seg) if (a <= ne && ne <= b) ne = b + 1;
    for (auto [a, b] : seg | views::reverse) if (a <= pr && pr <= b) pr = a - 1;

    if (ne > n || (pr >= 1 && abs(school-pr) <= abs(school-ne)))
        cout << pr << '\n';
    else
        cout << ne << '\n';
}

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

    int z = 1;
    // cin >> z;
    rep(_, z) solve();

    cout << flush;
    _Exit(0);
}