#include <stdio.h>

int main(void) {

int a,n,m,i,count=0;

scanf("%d",&a);
scanf("%d",&n);
	for(m=1;m<=n;m++){int k=1;
		for(i=1;i<=m;i++){
			k*=a;
		
		
		}count=count+k;
	}

printf("%d",count);





	// your code goes here
	return 0;
}