#include <fstream>
using namespace std;

ifstream in("rucsac.in");
ofstream out("rucsac.out");

const int inf=1000000;
const int N=5006;
int v[N],p[N],g[N];

int main()
{
	int n,k,i,j;
	in>>n>>k;
	for(i=1;i<=n;i++)
		in>>g[i]>>p[i];
	for(i=1;i<=k;i++)
		v[i]=-inf;
	v[0]=0;
	for(i=1;i<=n;i++)
	{
		for(j=k-g[i];j>=0;j--)
		{
			if(v[j]!=-inf)
			{
				if(v[j+g[i]]<v[j]+p[i])
					v[j+g[i]]=v[j]+p[i];
			}
		}
	}
	
	out<<v[k];
	return 0;
}