#include <cstdio>
using namespace std;
int max(int a,int b)
{
    if(a>b)
        return a;
    return b;
}
int d[1001];
int main()
{
    freopen("energii.in","r",stdin);
    freopen("energii.out","w",stdout);
    int n,m,i,prod,cost,j,last,max1;
    scanf("%d%d",&n,&m);
    last=0;
    for(i=1;i<=n;i++)
    {
        scanf("%d%d",&prod,&cost);
        for(j=last;j>=0;j--)
            if(j+prod<=m)
        {
            d[j+prod]=max(d[j+prod],d[j]+cost);
            if(j+prod>last)
                last=j+prod;
        }
    }
    max1=0;
    for(i=m;i>=1;i--)
        if(d[i]>max1)
          max1=d[i];
    printf("%d",max1);
    return 0;
}