#include<cstdio>
using namespace std;
int n,gmax,i,j,x[10001],y[10001],p[5001],g[5001];
int main()
{
    freopen("rucsac.in","r",stdin);
    freopen("rucsac.out","w",stdout);
    scanf("%d%d",&n,&gmax);
    for(i=1;i<=n;i++)
        scanf("%d%d",&g[i],&p[i]);
    for(i=1;i<=n;i++)
    {
        x[g[i]]++;
        y[g[i]]=p[i];
    }
    for(i=1;i<=n;i++)
    {
        for(j=g[i];j<=gmax;j=j+g[i])
        {
            if(y[j]+g[i]>y[g[i]])
            {
                y[g[i]]=y[j]+g[i];
                x[j]++;
            }
        }
    }
    for(i=gmax;i>=1;i--)
            if(x[i]>0)
            {
                printf("%d",y[i]);
                break;
            }
    return 0;
}