Descr iption

将m个孩子从1到m编上号，按序号围坐成一个圈，从1号孩子开始数，每数到n时，被数到的孩子即离开圈子，然后从下一个孩子开始，再从1开始数，如此不断地数下去，只到只剩下最后一个孩子，问剩下的孩子是几号？

Input

输入为一组整数对，每个整数对占一行，整数对的第一个整数表示m，即孩子的个数，第二个整数表示n，即被数到n的孩子将离开。

0＜m＜10000, n＞0

输入以0 0作为结束。

Output

每组整数对输出一个结果整数，每个输出占一行。

最后一行输入0 0不产生输出。-Descr iption will be m children from 1 to m made on the number, by serial number around a circle, from the beginning of the number of children on the 1st of each number to the n when the number of children to leave the circle, and then from the beginning of a child , from the beginning of a few, so keep going, only that there are only a child, asked the remaining child is a few number? Input integer input for a group of right, each integer on the line, rounded to an integer that the first m, that is, the number of children, the second integer, said n, the n was the number of children will leave. 0 <m <10000, n> 0 input to 0 0 as the end. Output each integer integer output a result, each output line. The last line of input 0 0 does not produce output.