#include <iostream>
#include <fstream>
using namespace std;
int q[10000001],p[1000001];
struct aa {int x,y;};
aa v[1002];
int main()
{
    ifstream fin ("energii.in");
    ofstream fout ("energii.out");
    int n,k,i,j;
        fin>>n>>k;
    for(i=1; i<=n; i++)
        fin>>v[i].x>>v[i].y;
    q[0]=1;
    p[0]=0;
    for(i=1; i<=n; i++)
    {
        for(j=k; j>=0; j--)
            if(q[j]==1)
            {
                q[j+v[i].x]=1;
                p[j+v[i].x]=p[j]+v[i].y;
            }
    }
    for(i=k; i<=10000000; i++)
        if(q[i]!=0)
        {
            fout<<p[i];
            break;
        }
    return 0;
}