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
#include <bits/stdc++.h> 
using namespace std;
#define st first
#define nd second
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
vector<pll> V;
map<ll,ll> skokl;
map<ll,ll> skokr;
const ll oo = (1e+18);

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll N , M , l , r;
    cin >> N >> M;
    ll S;
    cin >> S;
    for(int i =0 ; i < M  ; i++)
    {
        cin >> l >> r;
        V.push_back({l,r});
        skokl[r] = l-1;
        skokr[l] = r+1;
    }

    sort(V.begin() , V.end());
    ll res = oo; ll ind = 0;
    for(int i = 0 ; i < M ; i++)
    {
        ll disl = 0 ,disr = 0;
        l = V[i].st;
        while(skokr[l] != 0)l = skokr[l];

        r = V[i].nd;
        while(skokl[r] != 0)r = skokl[r];

        disr = abs(r-S);
        disl = abs(l-S);
        if(V[0].nd == r && V[0].st == 1)
        {
            disr = oo;
        }
        if(l == N+1)
        {
            disl = oo;
        }

        if(disl < res)
        {
            ind = l;
        }
        if(disl == res)
        {
            ind = min(ind , l);
        }
        res = min(res , disl);

        if(disr < res)
        {
            ind = r;
        }
        if(disr == res)
        {
            ind = min(ind , r);
        }
        res = min(res , disr);
    }

    cout << ind << '\n';

    
    return 0;
}