数据太水了，真建议大修此题

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int N=5e4+10;
ll n,m,k,ans,sum;
priority_queue<pair<int,int> >p;
priority_queue<int,vector<int>,greater<int> >q;
int main()
{
	scanf("%lld%lld%lld",&n,&k,&m);
	for(int i=1;i<=n;i++)
	{
		ll a,b;
		scanf("%lld%lld",&a,&b);
		p.push(make_pair(-b,a));
	}
	while(k--)
	{
		ll t=-p.top().first;
		ll x=p.top().second;
		p.pop();
		if(sum+t>m)break;
		sum+=t;
		ans++;
	}
	while(p.size())
	{
		ll t=-p.top().first;
		ll x=p.top().second;
		p.pop();
		q.push(x);
	}
	while(q.size())
	{
		ll x=q.top();
		q.pop();
		if(sum+x>m)break;
		sum+=x;
		ans++;
	}
	printf("%lld\n",ans);
		
	
	return 0;
}