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
#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

int main(){
    cin.tie(0)->sync_with_stdio(0);

    LL n,m,s;
    cin>>n>>m>>s;

    vector<pair<LL,LL>> tab(m);
    for(LL i=0;i<m;i++)cin>>tab[i].first>>tab[i].second;

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

    LL start = -1;

    for(LL i=0;i<m;i++){
        if(s>=tab[i].first && s<=tab[i].second)start=i;
    }
    if(start==-1){
        cout<<s<<endl;
        return 0;
    }
    LL ans1=tab[0].first-1;
    for(LL i=start-1;i>=0;i--){
        if(tab[i+1].first-1>tab[i].second){
            ans1=tab[i+1].first-1;
            break;
        }
    }
    LL ans2=tab[m-1].second+1;
    for(LL i=start+1;i<m;i++){
        if(tab[i-1].second+1<tab[i].first){
            ans2=tab[i-1].second+1;
            break;
        }
    }
    if(ans1<1){
        cout<<ans2<<endl;
    }else if(ans2>n){
        cout<<ans1<<endl;
    }else{
        if(abs(s-ans1)<=abs(s-ans2))cout<<ans1<<endl;
        else cout<<ans2<<endl;
    }


    return 0;
}