#include <iostream>
using namespace std;
#include <fstream>
ifstream f("energii.in");
ofstream g("energii.out");

int main() {
    int G, W, c_min;
    f>>G;
    f>>W;
    int EG[G];
    int CG[G];
    for(int i = 1; i<= G; i++){
        f>>EG[i];
        f>>CG[i];
    }
    /*int aux;
    for(int i = 1; i<= G; i++){
        for(int j = i; j<=G; j++){
            if(CG[j+1] > CG[j]){
                aux = CG[j];
                CG[j] = CG[j+1];
                CG[j+1] = aux;
            }
        }
    }
    */

    int sum_e[G];
    sum_e[0] = EG[0];
    for(int i = 1; i <= G; i++){
        sum_e[i] = sum_e[i - 1] + EG[i];
    }
    // 2 4 12
    // 4 7 16
    int sum_c[G];
    sum_c[0] = CG[0];
    for(int i = 1; i <= G; i++){
        sum_c[i] = sum_c[i - 1] + CG[i];
    }

    c_min = 10000;

    for(int i = 1; i<= G; i++){
        if(sum_e[i] >= W){
            c_min = CG[i];
        }
    }
    g<<c_min;
    return 0;
}