#include <fstream>
using namespace std;

ifstream f("energii.in");
ofstream g("energii.out");

int n, w, Min=2e9, GMax;
int a[1001], b[1001];
int v[1001][5001];

int main()
{
    f>>n>>w;
    for(int i=1; i<=n; i++)
        f>>a[i]>>b[i];
    for(int i=1; i<=n; i++)
    {
        for(int j=1; j<=w+1; j++)
        {
            if(b[i]>j)
                v[i][j]=v[i-1][j];
            else
                v[i][j]=max(v[i-1][j], v[i-1][j-b[i]]+a[i]);
            if(v[i][j]>=w)
                Min=min(v[i][j], Min);
        }
    }
    g<<Min;
    return 0;
}