有M个敢死队员要炸掉敌人的一碉堡，谁都不想去，排长决定用轮回数数的办法来决定哪个战士去执行任务。如果前一个战士没完成任务，则要再派一个战士上去。现给每个战士编一个号，大家围坐成一圈，随便从某一个战士开始计数，当数到5时，对应的战士就去执行任务，且此战士不再参加下一轮计数。如果此战士没完成任务，再从下一个战士开始数数，被数到第5时，此战士接着去执行任务。以此类推，直到任务完成为止。

　 排长是不愿意去的，假设排长为1号，请你设计一程序，求出从第几号战士开始计数才能让排长最后一个留下来而不去执行任务。-The M members of death squads to blow up the enemy bunker, no one wanted to go, platoon leader decided to a transmigration count approach to decide which fighters to perform the task. If you did not complete the task before a soldier, will have to send another one of the soldiers up. Now compiled a number to each soldier, we were sitting in a circle, casually counted from the beginning of a warrior, count to 5, corresponding to the soldiers went to perform the task, and the soldiers no longer participate in the next round of counting. If soldiers did not complete the task, from a soldier began to count, count to 5, this warrior went on to perform the task. And so on, until the task is completed so far.

Platoon leader is not willing to go, it is assumed that the platoon leader for the 1st, you design a program, calculated from the number of soldiers began counting to let the platoon leader last stay and not to perform the task