请求大佬帮调

#include<cstdio>
#include<iostream>
#include<cstring>
#include<string>
#include<cmath>
#include<algorithm>
using namespace std;
int n,s,a,b,sum;
struct add{
	int x,y;
}ans[5005];
int main(){
	scanf("%d%d%d%d",&n,&s,&a,&b);
	for(int i=1;i<=n;++i)
		scanf("%d%d",&ans[i].x,&ans[i].y); 
	for(int i=1;i<=n;++i){
		for(int j=1;j<=n-i;++j){
			if(ans[j].y>ans[j+1].y)
				swap(ans[j],ans[j+1]);
		}
	} 
	int i=1;
	while(s-ans[i].y>=0&&i<=n){
		if(b+a>=ans[i].x)
			++sum;
		s-=ans[i].y;
		++i;
	}
	printf("%d",sum);
	return 0;
}