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
79
80
81
82
83
84
85
86
87
88
89
90
91
92
#include <vector>
#include <cstdio>
#include <stack>
#include <algorithm>
#include <queue>
#include <map>
#include <cmath>
#include <unordered_set>
#include <unordered_map>
#include <set>
#include <cstring>
#include <bitset>
#include <iostream>
#include <queue>
#include <iomanip>
#include <complex>

using namespace std;

#define ALL(x) x.begin(), x.end()
#define UNIQUE(c) (c).resize(unique(ALL(c)) - (c).begin())
#define FOR(i, a, b) for(int i =(a); i <=(b); ++i)
#define RE(i, n) FOR(i, 1, n)
#define RED(i, n) FORD(i, n, 1)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)
#define REP(i, n) for(int i = 0;i <(n); ++i)
#define REPD(i, n) FORD(i, n-1,0)

#define printA(a, L, R) FOR(i,L,R) cout << a[i] << (i==R?'\n':' ')
#define printV(a) printA(a,0,a.size()-1)
#define PRESENT(c, x) ((c).find(x) != (c).end())
#define CPRESENT(c, x) (find(ALL(c),x) != (c).end())
#define bit(x, i) (x&(1<<i))
#define lowbit(x) ((x)&((x)^((x)-1)))

const int fx[4][2] = {{0,  1},
                      {0,  -1},
                      {1,  0},
                      {-1, 0}};
const int fxx[8][2] = {{0,  1},
                       {0,  -1},
                       {1,  0},
                       {-1, 0},
                       {1,  1},
                       {1,  -1},
                       {-1, 1},
                       {-1, -1}};
const int sk[8][2] = {{2,  1},
                      {2,  -1},
                      {-2, -1},
                      {-2, 1},
                      {1,  2},
                      {-1, 2},
                      {1,  -2},
                      {-1, -2}};

const int maxn = 8012;
long long mod = 998244353ll;
const long long inf = 10000000000012ll;

long long n, m, s, a, b, p = inf, su;
void solve() {
    set<pair<long long, int> > se;
    cin>>n>>m>>s;
    REP(i, m) {
        cin>>a>>b;
        se.emplace(a, -1);
        se.emplace(b + 1, 1);
    }
    for (auto &[a, b]: se) {
        if (su == 0 && a > 1 && abs(p - s) > abs(s - (a - 1))) {
            p = a - 1;
        }
        su -= b;
        if (su == 0 && abs(p - s) > abs(s - a) && a <= n) {
            p = a;
        }
        // cout<<p<<"\n";
    }
    cout<<p<<"\n";
}

int main() {
    ios_base::sync_with_stdio(false), cin.tie(nullptr);

    int tt = 1;
//    cin >> tt;`
    while (tt--) {
        solve();
    }
    return 0;
}