Don Colton's Risk Dice Roller

(Risk is a trademark of Parker Bros / Hasbro for their board game.)
Wikipedia Article, Attacking

How many attacking armies
How many defending armies
How many skirmishes (max)

Skirmish 1   2 5 5   2 2 attacker loses X, defender loses X
Skirmish 2   2 4 5   2 4 attacker loses X, defender loses X
Skirmish 3   4 5 1   3 5 attacker loses X, defender loses X
Skirmish 4   4 1 5   1 5 attacker loses X, defender loses X