rt
#include <stdio.h>

int main() {
	while(1){
		int n,k;
		if(scanf("%d%d", &n, &k) != 2) break;
		int t = 0;
		int z = n, s = 0;
		while(1){
			t += z;
			s += z;
			z = s/k;
			s = s%k;
			if(!z) break;
		}
		printf("%d\n", t);
	}
	return 0;
}