Problem H: Eat Candy

Problem H: Eat Candy

Time Limit: 1 Sec   Memory Limit: 128 MB
Submit: 1329   Solved: 643
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Description

   There is a box with infinite volume. At first there are n candies in the box. Then every second you will eat some candies, left half of candies (round down) in the box. Then add k candies into the box. How many candies there are in the box after 109+7 seconds?

Input

   There are multiple test cases. In each test case, there are only one line contains two integers n,k(1≤n,k≤109+7)

Output

    For each test case, output the answer in one line.

Sample Input

4 5
2 3

Sample Output

9
5

HINT

In the first test case:

1st second, 4->2, 2+5 = 7

2nd second, 7->3, 3+5 = 8

3rd second, 8->4, 4+5 = 9

4th second, 9->4, 4+5 = 9

…

1000000007th            9

So there are 9 candies in the box after 1000000007 seconds.

#include<stdio.h>
#include<string.h>
#include<math.h>
int main()
{
	long a,b,i,re,t;
	while(scanf("%ld %ld",&a,&b)!=EOF)
	{
		re=a/2;
		while(1)
		{
			t=re;
			re+=b;
			re=re/2;
			if(t==re)
			{
				printf("%ld\n",t+b);
				break;
			}
		}
	}
	return 0;
}