P1150 Peter的烟

#include<stdio.h>
int main(){
    long int n, k, res;
    scanf("%ld%ld", &n, &k);
    res = n;
    while(n/k){
        res += (n / k);
        n = n % k + n / k;
    }
    printf("%ld", res);
    return 0;
}