There is a creature with many heads, one knight wants to kill it. He can cut 1, 7 or 11 heads off.
If there is any head left:
I) After cutting 1 head off, 4 heads will grow.
II) After cutting 7 heads off, 1 head will grow.
III) After cutting 11 heads off, 5 heads will grow.
Creature dies when there isn't any head left.
Can knight kill it
1. If it has got 100 heads?
2. If it has got 99 heads?