D&D script to calculate the damage made by a squad of minions

minion_squad.py

from math import ceil, floor

# inputs 
quantity = (int(raw_input("Minions left: ")))
roll = (int(raw_input("Roll: ")))
target = (int(raw_input("Target AC: ")))

# minion attack details
bonus = 15
damage = 10

# internal variable
number_hit = 0

threshold = target - bonus

upper_half_quantity = (int(ceil(float(quantity)/2)))
lower_half_quantity = (int(floor(float(quantity)/2)))

for x in range(1, upper_half_quantity + 1):
	if roll + (x * 2) > threshold:
		number_hit += 1

print "Damage = " + str(damage * number_hit)