不愧是我

#include<bits/stdc++.h>
using namespace std;
struct n {
	int w, v;
} a[110];
bool cmp(n x, n y) {
	return x.vy.w > x.wy.v;
}
int main() {
	int n, m;
	cin >> n >> m;
	double ans = 0;
	for (int i = 0; i < n; i++) cin >> a[i].w >> a[i].v;
	sort(a, a + n, cmp);
	for (int i = 0; i < n; i++)
		if (a[i].w <= m) ans += a[i].v, m -= a[i].w;
		else {
			ans += a[i].vm1.0 / (double)a[i].w;
			break;
		}
	printf("%.2lf", ans);
	return 0;
}