Create a function that takes a string and returns that
string with the first half lowercased and the last half uppercased.
eg: foobar == fooBAR
If it is an odd number then 'round' it up to find which letters to uppercase. See example below.
    sillycase("brian")  
    //         --^-- midpoint  
    //         bri    first half (lower-cased)  
    //            AN second half (upper-cased)
import math

def sillycase(silly):
    if len(silly) % 2 == 0:
        even_half = len(silly) // 2
        return silly[:even_half].lower() + silly[even_half:].upper()
    else:
        odd_half = math.ceil(len(silly) / 2)
        return silly[:odd_half].lower() + silly[odd_half:].upper()
import math

def sillycase(silly):
    if len(silly) % 2 == 0:
        even_half = len(silly) // 2
        return silly[:even_half].lower() + silly[even_half:].upper()
    else:
        odd_half = math.ceil(len(silly) / 2)
        return silly[:odd_half].lower() + silly[odd_half:].upper()