#include <fstream>
#include <cstring>
using namespace std;

ifstream is("energii.in");
ofstream os("energii.out");

int n, s;
int suma;
int p[1001], c[1001];
int q[15005];

int main()
{
    is >> n >> s;
    for ( int i = 1; i <= n; ++i )
        is >> p[i] >> c[i];
    memset(q, -1, 15005);
    q[0] = 0;
    for ( int i = 1; i <= n; ++i )
    {
        for ( int j = suma; j > -1; --j )
            if ( q[j] != -1 && q[j] + c[i] > q[j + p[i]] )
                q[j + p[i]] = q[j] + c[i];
        suma += p[i];
    }
    for ( int i = s; i <= suma; ++i )
        if ( q[i] != -1 )
        {
            os << q[i];
            break;
        }
    is.close();
    os.close();
    return 0;
}