#include <fstream>

using namespace std;

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

int n,s,g[5005],p[5005],v[5005];

inline int maxim(int x,int y)
{
	return x > y ? x : y;
}

void citire()
{
	in>>n>>s;
	for(int i=1;i<=n;++i)
		in>>g[i]>>p[i];
	for(int i=1;i<=s;++i)
		v[i]=-1;
	for(int i=1;i<=n;++i)
		for(int j=s-g[i];j>=0;--j)
			if(v[j]!=-1)
				v[j+g[i]]=max(v[j+g[i]],v[j]+p[i]);
	out<<v[s];
}
	

int main()
{
	citire();
	return 0;
}