cigarettes

题目描述

Tom has many cigarettes. We hypothesized that he has n cigarettes and smokes them

one by one keeping all the butts. Out of k > 1 butts he can roll a new cigarette. 
Now，do you know how many cigarettes can Tom has?

输入

First input is a single line,it's n and stands for there are n testdata.then there are n lines ,each line contains two integer numbers giving the values of n and k.

输出

For each line of input, output one integer number on a separate line giving the maximum number of cigarettes that Peter can have.

样例输入

3
4 3
10 3
100 5

样例输出

5
14
124

代码

#include<stdio.h>
int main()
{
	int a;
	scanf("%d",&a);
	while(a--)
	{
		int n,k,sum;//有n个烟,每k根烟灰就能再换一根烟
		scanf("%d %d",&n,&k);
		sum=n;
		while(n/k)
		{
			sum+=n/k;
			n=n/k+n%k;
		}
		printf("%d\n",sum);	
	}
	return 0;
}