#include <iostream>
#include <fstream>
#include <vector>
#include <vector>
#define eg first
#define cg second
using namespace std;
ifstream in("energii.in");
ofstream out("energii.out");
vector < pair<double,double> > v;
int g,w,s,c;
void sortare(){
    for(int i=0;i<g-1;i++)
        for(int j=i+1;j<g;j++)
            if(v[i].cg/v[i].eg>v[j].cg/v[j].eg)
                swap(v[i],v[j]);
}
int main(){
    in>>g>>w;
    for(int i=1;i<=g;i++){
        double a,b;
        in>>a>>b;
        v.push_back(make_pair(a,b));
    }
    sortare();
    for(int i=0;i<g;i++){
        cout<<v[i].eg<<" "<<v[i].cg<<endl;
    }
    for(int i=0;i<g;i++){
        s+=v[i].eg;
        c+=v[i].cg;
        if(s>=w){
            out<<c;
            return 0;
        }
    }
    out<<-1;
    return 0;
}