改之前点1没过 改完后就点1过了其他都没过 蒟蒻求调[悲
（变量名瞎起的

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

int n, i, t;

struct golds{
	int v, m, value;
}gold[110];

bool cds(golds a, golds b){
	return a.value > b.value;
}

int solve(){
	int money = 0, a = 0;
	while (t){
		if (t > gold[a].m){
			t -= gold[a].m;
			money += gold[a].v;
			a++;
		} else {
			money += gold[a].value * t;
			break;
		}
	}
	return money;
}

int main(){
	int e = 0, io;
    cin >> n >> t;
    for (i = 0; i < n; i++){
    	cin >> gold[i].m >> gold[i].v;
    	gold[i].value = gold[i].v / gold[i].m;
    	ee += gold[i].m;
    	io += gold[i].v;
	}
	if (ee < t){
		cout << io << ".00" << endl;
		return 0;
	}
	sort(gold + 1, gold + n + 1, cds);
	cout << solve() << ".00"<<endl;
	return 0;
}