#include <iostream>
#include <fstream>
using namespace std;
ifstream f("energii.in");
ofstream h("energii.out");
int n,e,cost;
struct generatoare
{
    float e,c;
}g[1001];
void citire()
{
    f>>n>>e;
    for(int i=1;i<=n;i++)
    f>>g[i].e>>g[i].c;
    cout<<g[3].e/g[3].c;
}
void solve()
{
    int var=0;
    for (int i=1;i<n;i++)
        for (int j=i+1;j<=n;j++)
            if(g[i].e/g[i].c<g[j].e/g[j].c)
            swap(g[i],g[j]);
    cout<<g[1].c;
    for (int i=1;i<=n && var<e;i++)
    {
        var+=g[i].e;
        cost+=g[i].c;
    }
    if(var>=e)
    h<<cost;
    else h<<-1;
}
int main()
{
    citire();
    solve();
    return 0;
}