#include<bits/stdc++.h>
using namespace std;
bool cmp(node a,node b){
    return a.m/a.v>b.m/b.v;
}
struct node{
    int m,v;
}a[105];
int main(){
    int n,t,ans=0,ans2=0;cin>>n>>t;
    for(int i=1;i<=n;i++) cin>>a[i].m>>a[i].v;
    sort(a+1,a+n+1,cmp);
    for(int i=1;i<=n;i++){
        if(ans2<t){
            ans+=a[i].v;
            ans2+=a[i].m;
        }
        else{
            ans-=a[i-1].v;
            ans2-=a[i-1].m;
        }
    }
    cout<<ans<<".00";
	return 0;
}