#include<fstream>

using namespace std;

int main()
{
    ifstream fin("sumdiv.in");
    ofstream fout("sumdiv.out");
int a,b,i,s=1,t=1;
fin>>a>>b;
for(i = 1; i <= b; i++)
{
      t*=a;
      s+=t;
}
fout<<s;

fin.close();
fout.close();

return 0;
}