A system of two blocks of masses \( m = 2 \, \text{kg} \) and \( M = 8 \, \text{kg} \) is placed on a smooth table as shown in figure. The coefficient of static friction between two blocks is \( 0.5 \). The maximum horizontal force \( F \) that can be applied to the block of mass \( M \) so that the blocks move together will be:
