蒟蒻80分求助(;´༎ຶД༎ຶ`)

#include <iostream>
#include<algorithm>
using namespace std;
typedef struct zsg{
    int h;
    int lq;

}zsg;

bool cmp2(zsg a,zsg b){
    return a.lq<b.lq;
}
int main(){
    int n,s,a,b;
    cin>>n>>s;
    cin>>a>>b;
    zsg zb[5005];
    for(int i=0;i<n;i++){
        scanf("%d %d",&zb[i].h,&zb[i].lq);
    }
    sort(zb,zb+n,cmp2);
    int sum=0;
    int i=0;
    int sum2=0;
    while(sum<=s&&i<n){
        if(zb[i].h<=(a+b)){
        sum2++;
        sum+=zb[i].lq;
        }
        i++;
    }   
    if(sum<s) cout<<sum2;
    if(sum>=s) cout<<sum2-1;
}