#include <stdio.h>

int main(void) {
int a, n;
int terms[10];
int sum = 0;
int temps = 1;

scanf("%d", &a);
scanf("%d", &n);

for (int i = 0; i < n; i++)
{temps = temps * a;
terms[i] = temps;
sum = sum + terms[i];
}

printf("%d", sum);
return 0;
}