没有ac的时候记得输出-1
#include <iostream>
#include <cstdio>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <set>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <stack>
#define INF 0x3f3f3f3f
#define LINF 0x3f3f3f3f3f3f3f3f
#define ll long long
#define ull unsigned long long
#define uint unsigned int
#define l(x) ((x)<<1)
#define r(x) ((x)<<1|1)
#define lowbit(x) ((x)&(-(x)))
#define abs(x) ((x)>=0?(x):(-(x)))
#define ms(a,b) memset(a,b,sizeof(a))
#define NSYNC std::ios::sync_with_stdio(false);std::cin.tie(0);std::cout.tie(0);
using namespace std;
struct node{
int val,cost;
int opo;
bool operator<(const node &a){
return val<a.val;
}
};
int n,c,f,cl,cr;
node demo[222222];
priority_queue<int> q,qq;
int main(){
NSYNC;
cin>>n>>c>>f;
for(int i = 0;i<c;i++){
cin>>demo[i].val>>demo[i].cost;
}
sort(demo,demo+c);
cl = cr =0;
for(int i = 0;i<n/2;i++) cl+=demo[i].cost,q.push(demo[i].cost);
for(int i = n/2;i<c;i++){
demo[i].opo = cl + demo[i].cost;
cl+=demo[i].cost;
q.push(demo[i].cost);
cl-=q.top();
q.pop();
}
for(int i = c-1;i>c-n/2-1;i--) cr+=demo[i].cost,qq.push(demo[i].cost);
for(int i = c-n/2-1;i>=0;i--){
demo[i].opo += cr;
cr+=demo[i].cost;
qq.push(demo[i].cost);
cr-=qq.top();
qq.pop();
}
bool flag = false;
for(int i = c-n/2-1;i>=n/2;i--){
//cout<<demo[i].opo<<" ";
if(demo[i].opo<=f){
printf("%d\n",demo[i].val);
flag = true;
break;
}
}
//cout<<endl;
if(!flag)printf("-1\n");
int nnn;
cin>>nnn;
return 0;
}