80分没过，求大佬看看

#include<iostream>
#include<algorithm>
using namespace std;
struct aa
{
    int a;//高
    int b;//力气
}ss[5100];
bool cmp(aa x, aa y)
{
    if (x.b < y.b)return 1;
    return 0;
}
int main()
{
    int n, s, a, b, a1[5100], a2[5100], j=0;
    cin >> n >> s;
    cin >> a >> b;
    for (int i = 0; i < n; i++)
    {
        cin >> a1[i] >> a2[i];
        if (a1[i] <= a + b)
        {
            ss[j].a = a1[i];
            ss[j].b = a2[i];
            j++;
        }
    }
    sort(ss, ss + j, cmp);
    int x = 0;
    int m = 0;
    for (int i = 0; i <= j; i++)
    {
        x += ss[i].b;
        if (x > s)
        {
            cout << m;
            break;
        }
        m++;
    }
    return 0;
}