#include <bits/stdc++.h>

using namespace std;
ifstream in("gfact.in");
ofstream out("gfact.out");

int main()
{
    int n,m,nrq,lst=1,ldr=500000000,c,p,q,aux;
    in>>p>>q;
    if(n==0)
    {
        out<<1;
        return 0;
    }
    while(lst <= ldr)
    {
        m = (lst + ldr) / 2;
        c=0;
        aux=p;
        while(m >= aux)
        {
            c += m / aux;
            aux *= p;
        }
        nrq=c;
        if(nrq==q)
        {
            m-=m%p;
            out<<m;
            return 0;
        }
        else if(nrq<q)
            lst = m + 1;
        else
            ldr = m - 1;
    }
    out<<-1;
    return 0;
}