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
#include <bits/stdc++.h>
#define ff first
#define ss second
using namespace std;

long long n, m, s;
vector <pair<long long, long long>>v;

vector <long long> ciag;

long long mini_odl;
long long dom;

int main() {

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

cin >> n >> m >> s;

mini_odl = n + 5;

for (int i=0; i<m; i++) {

    long long a, b;

    cin >> a >> b;

    v.push_back(make_pair(a, b));

}

v.push_back(make_pair(0, 0));
v.push_back(make_pair(n+1, n+1));

sort(v.begin(), v.end());


for (int i=1; i<v.size()-1; i++) {

    if (i==1) {
        if (v[i].ff > 1) {ciag.push_back(v[i].ff-1);}
        if (v[i].ss != v[i+1].ff - 1) {ciag.push_back(v[i].ss+1), ciag.push_back(v[i+1].ff-1);}
    }

    else if (i==v.size()-2) {
        if (v[i].ss < n) {ciag.push_back(v[i].ss+1);}
        if (v[i].ff != v[i-1].ss + 1) {ciag.push_back(v[i].ff-1); ciag.push_back(v[i-1].ss+1);}
    }

    else {
        if (v[i].ss != v[i+1].ff - 1) {ciag.push_back(v[i].ss+1), ciag.push_back(v[i+1].ff-1);}
        if (v[i].ff != v[i-1].ss + 1) {ciag.push_back(v[i].ff-1); ciag.push_back(v[i-1].ss+1);}
    }

}

for (int i=0; i<ciag.size(); i++) {

    long long odl = abs(s-ciag[i]);

    if (odl < mini_odl) {

        dom = ciag[i];
        mini_odl = odl;

    }

}
cout << dom << endl;
}