#1#3#5WA求助

代码：

#include <iostream>
#include <algorithm>
using namespace std;

struct st
{
    int x, y;
};
bool cmp(st a, st b)
{
    return a.y < b.y;
}
st c[5001];
int main()
{
    int n, s, cnt = 0;
    cin >> n >> s;
    int a, b;
    cin >> a >> b;
    for (int i = 1; i <= n; ++i)
    {
        cin >> c[i].x >> c[i].y;
    }
    sort(c + 1, c + n + 1, cmp);
    for (int i = 1; i <= n; ++i)
    {
        if (s - c[i].y < 0 || a + b < c[i].x)
        {
            break;
        }
        cnt++;
        s -= c[i].y;
    }
    cout << cnt << endl;
    return 0;
}