#include <iostream>
#include <cstdio>
using namespace std;

int main() {
	int a, b, cnt=0;
	scanf("%d%d", &a, &b);
	cnt+=a;
	while(a>=b) {
		cnt+=a/b;
		a=a/b+a%b;
	}
	printf("%d", cnt);
	return 0;
}