感觉写的好像没问题，但是输入前两个值之后就结束了。有点懵，求找错

#include<stdio.h>
#include <stdlib.h>
typedef struct pingguo
{
    int x;
    int y;
}apple;
apple k[5001];
int cmp(const void*p,const void*q)
{
    return (*(apple *)p).y - (*(apple *)q).y;  
    }
int main()
{
    int num=0;
    int n,s,a,b;
    int h=a+b;
    scanf("%d %d",n,s);
    scanf("%d %d",a,b);
    for(int i=0;i<n;i++)
    {
        scanf("%d%d",k[i].x,k[i].y);
    }
    qsort(k,n,sizeof(apple),cmp);
    for(int i=0;i<n;i++)
    {
        if(k[i].x<=h&&k[i].y<=s)
        {
            num++;s-=k[i].y;
        }

    }
    printf("%d",num);
}