抄

#include <bits/stdc++.h>
using namespace std;
struct Apple {
int height, qe;
};
bool rt(const Apple& a, const Apple& b) {
return a.qe < b.qe;
}
int mx(int n, int s, int a, int b, vector<Apple>& apples) {
sort(apples.begin(), apples.end(), rt);

int count = 0; 
for (const auto& apple : apples) {
    if (s >= apple.qe) { 
        if (apple.height <= b || (apple.height - a) <= b) {
            s -= apple.qe; 
            count++; 
        }
    } else {
        break;
    }
}
return count;

}
int main() {
int n, s, a, b;
cin >> n >> s >> a >> b;
vector<Apple> apples(n);
for (int i = 0; i < n; ++i) {
cin >> apples[i].height >> apples[i].qe;
}
cout << mx(n, s, a, b, apples) << endl;
return 0;
}