'''
Created on Sep 28, 2017

@author: Susan
'''


def mystery(strng, letter):
    pos = 0
    count = 0
    result = ''
    while count < 4 and pos < len(strng):
        if strng[pos] == letter:
            result += strng[pos] + strng[pos]
            count += 1
        else: 
            result += strng[pos]
        pos += 1
    result += strng[pos:]    
    return result

print mystery("September December", "e")


def mystery2(strng, letter):
    pos = 0
    count = 0
    result = ''
    while True:
        # missing code to break out of while
        if count >= 4:
            break
        if pos >= len(strng):
            break
        if strng[pos] == letter:
            result += strng[pos] + strng[pos]
            count += 1
        else: 
            result += strng[pos]
        pos += 1
    result += strng[pos:]    
    return result


print mystery2("September December",'e')
print mystery2("September December",'m')