Рожден ден

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <queue>

using namespace std;

struct Guest{
    int comes;
    int goes;
    int index;
};

struct comeComparator{
    bool operator()(Guest g1, Guest g2) const{
        return g1.comes > g2.comes;
    }
};
struct goComparator{
    bool operator()(Guest g1, Guest g2) const{
        return g1.goes > g2.goes;
    }
};



int main() {
    int n, a, b, t;
    priority_queue<Guest, vector<Guest>, comeComparator> expect;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> there; //goes, chair
    priority_queue<int, vector<int>, greater<int>> chairs;

    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> a >> b;
        expect.push({a, b, i});
        chairs.push(i);
    }
    int currTime = 0;
    cin >> t;

    while(!expect.empty()){
        while(expect.top().comes <= currTime){
            if(expect.top().index == t){
                cout << chairs.top();
                return 0;
            }
            there.push({expect.top().goes, chairs.top()});

            chairs.pop();
            expect.pop();
        }
        while(!there.empty() && there.top().first <= currTime){
            chairs.push(there.top().second);
            there.pop();
        }
        if(!expect.empty()){
            currTime = expect.top().comes;
            if(!there.empty())
                currTime = min(currTime, there.top().first);
        }
    }


    return 0;
}