#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,t;
    cin>>n>>t;
    double a[n],b[n],c[n],s=0;
    for (int i=0;i<n;i++){
        cin>>a[i]>>b[n];
        c[n]=1.0*b[n]/a[n];
    }
    sort(c,c+n);
    for (int i=n;i>=0;i--){
        if (t>=a[i]){
            s+=1.0*c[n];
            t-=a[n];
        }
    }
    cout << fixed << setprecision(2) << s;
}