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

const string fis = "rucsac";
ifstream is(fis + ".in");
ofstream os(fis + ".out");

using VI = vector<int>;
using VVI = vector<VI>;

int n, m, g, p;
VI q;

int main()
{
    is >> n >> m;
    q = VI(m + 1);
    q[0] = 1;
    for ( int i = 1; i <= n; ++i )
    {
        is >> g >> p;
        for ( int j = m; j - g >= 0; --j )
            if ( q[j - g] )
                q[j] = max(q[j], q[j - g] + p);
    }
    ++m;
    while ( m-- )
        if ( q[m] )
        {
            os << q[m] - 1;
            m = 0;
        }
    is.close();
    os.close();
    return 0;
}