// energii.cpp : Defines the entry point for the console application.
//

#include "stdio.h"

FILE *fin=freopen("energii.in","r",stdin);
FILE *fout=freopen("energii.out","w",stdout);

int g,w,x[1001],c[1001],f[1001][5001];
void citeste()
{
	scanf("%d%d",&g,&w);
	for(int i=1;i<=g;i++)
	{
		scanf("%d%d",&c[i],&x[i]);
	}
	fclose(fin);
}
void rezolva()
{
	int i,j;
	for(i=1;i<=g;i++)
	{
		for(j=1;j<=w;j++)
		{
			if(c[i]<=j && x[i]+f[i-1][j-c[i]]>f[i-1][j])
			{
				f[i][j]=x[i]+f[i-1][j-c[i]];
			}
			else f[i][j]=f[i-1][j];
		}
	}
}
void afiseaza()
{
	printf("%d",f[g][w]);
	fclose(fout);
}

int main()
{
	citeste();
	rezolva();
	afiseaza();
	return 0;
}