Death By Firing Squad

You and your troop of N soldiers have been captured by the Evil Militia and been sentenced to death by firing squad.
 
Cruel or merciful, the Evil Militia will shoot all but one prisoner.
 
The order of execution is determined at the last minute when General Lee orders the official "shoot" number.
 
This number dictates the order in which the lined up prisoners will be shot. For example:
 
A "shoot" number of 3 indicates that every 3rd person in the line-up will be shot until one remains.
 
You have but seconds to decide where to stand in the line to avoid death by bullet.