#include <fstream>

using namespace std;
ifstream fin("conversie_b_10.in");
ofstream fout("conversie_b_10.out");
int n,b,x,n1=0,p,k=0,i;
int main()
{
    fin>>n>>b;
    p=1;
    while(n!=0)
    {
        x=n%10;
        for(i=1;i<=x;i++)
        {
            k=k+p;
        }
        n1=n1+k;
        k=0;
        p=p*b;
        n=n/10;
    }
    fout<<n1;
    return 0;
}