#include<cstdio>
const int M=10000000;
int g[5001],c[5001],s[10001],m,n,i,j,t,o;
char r[M];
inline int A()
{
  	int s=0;
  	for(;r[o]<48;o++);
  	for(;r[o]>47;o++)
  		s=s*10+r[o]-48;
  	return s;
}
int main()
{
    freopen("rucsac.in","r",stdin),freopen("rucsac.out","w",stdout),fread(r,1,M,stdin),n=A(),m=A();
    for(i=1;i<=n;i++)
        g[i]=A(),c[i]=A();
    for(i=1;i<=n;i++)
        for(j=m-g[i];j>=0;j--)
        	if(s[j+g[i]]<s[j]+c[i])
            	s[j+g[i]]=s[j]+c[i],t=s[j+g[i]]>t?s[j+g[i]]:t;
    printf("%d",t);
}