#include <bits/stdc++.h>
using namespace std;
ifstream in("energii.in");
ofstream out("energii.out");

int main()
{
    float g,w=0,c=0,ww=0;
    int i,j;
    float randament=0;
    float eg[1000],ec[1000];
    in>>g;
    in>>w;
    for(i=0;i<g;i++)
    {
        in>>eg[i]>>ec[i];
        if(randament < eg[i]/ec[i])
            {
                randament = eg[i]/ec[i];
                j=i;
            }
    }
    while(ww<w)
    {
        ww+=eg[j];
        c+=ec[j];
    }
    out<<c;
}