$RT$，都能被橙题搞晕啊，@王子腾0518真菜

$40pts\ Code$

#include <bits/stdc++.h>
using namespace std;
int n, s, a, b, addba;
struct Apples {
	int x, y;
} apple[5005];
bool cmp(Apples r, Apples w) {
	return r.y < w.y;
}
int main() {
	cin >> n >> s;
	cin >> a >> b;
	for (int i = 1; i <= n; i++) {
		cin >> apple[i].x >> apple[i].y;
	}
	addba = a + b;
	int j = 1, cnt = 0;
	sort(apple + 1, apple + n + 1, cmp);
	while (s >= 0) {
		if (j > n) {
			break;
		}
		if (apple[j].x <= addba) {
			s -= apple[j].y;
			cnt++;
		}
		j++;
	}
	cout << cnt;
	return 0;
}