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#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
     
int main() {
    //freopen("input.in", "r", stdin);
    //freopen("output.out", "w", stdout);
    ios_base::sync_with_stdio(0); 
    cin.tie(NULL);
    cout.tie(NULL);
    
    ll n,m,s;
    cin>>n>>m>>s;
    
    vector<pair<ll, ll>> pairs(m);
    for (ll i=0; i<m; i++) {
        cin>>pairs[i].first>>pairs[i].second;
    }
    
    sort(pairs.begin(), pairs.end());
    
    vector<pair<ll, ll>> new_pairs;
   
    new_pairs.push_back(pairs[0]);
   

    for (ll i=1; i<m; i++){
        if (new_pairs.back().second+1==pairs[i].first) {
            new_pairs.back().second=pairs[i].second;
        } 
        else{
            new_pairs.push_back(pairs[i]);
        }
    }

    // for (auto e:new_pairs){
    //     cout<<e.first<<"-"<<e.second<<endl;
    // }

    ll p1=-12, p2=-12;
    for (auto p:new_pairs) {
        if (p.first<=s and s<=p.second) {
            if (p.first-1==0) {
                p1=-12;
            } 
            else{
                p1=p.first-1;
            }
            if (p.second+1==n+1) {
                p2 = -12;
            } 
            else{ 
                p2=p.second+1;
            }
            break;
        }
    }


    //cout<<p1<<"-"<<p2<<endl;

    if(p1==-12){
        cout<<p2<<endl;
    }
    else if(p2==-12){
        cout<<p1<<endl;
    }
    else{
        if(abs(s-p1)<=abs(s-p2)){
            cout<<p1<<endl;
        } else {
            cout<<p2<<endl;
        }
    }
    return 0;
}