How can I create three random integers which sum to a specific value? (Python)

Let's say bob = 6

I want to create 3 random integers that have a sum of 106 (100 + whatever bob's original integer is. It could be 10, but in this case, it's 6).

I've got:

from random import *
bob = 6
bob1 = (randint(0,100))
bob2 = (randint(0,100))
bob3 = (randint(0,100))
print bob1
print bob2
print bob3

I can generate integers, but how can I make sure the sum of them = 100 + original integer? (106 total). If the sum doesn't = 106, then I want the script to keep going until it makes 106.