'''
Created on Sep 16, 2014

Created with CompSci 101 Sec 02

@author: Susan
'''
def minutesNeeded (numCakes, capacity):
    '''
    DO NOT IF INPUT RETURN OUTPUT OR YOU WILL DIE!!!
    if numCakes == 9 and capacity == 6:
        return 15
    if numCakes == 13 and capacity == 6:
        return 25
    '''
    
    # exactly full or less than full
    if numCakes == 0: # there is nothing to cook
        return 0
    if numCakes <= capacity:  
        return 10
    # pan always full   8 4
    if numCakes % capacity == 0:
        return numCakes/capacity * 10
    # extra pancakes fill half or less of the pan
    temp = (numCakes % capacity)/float(capacity)
    if  temp <= 0.5:
        temp2 = numCakes/capacity
        return temp2 * 10 + 5
    # extra amount is more than half capacity
    if temp > 0.5:
        return numCakes/capacity *10 + 10


print minutesNeeded(7,4)