Two dice: simulation against exact

You will find the exact probability of each sum of two dice by listing the 36 pairs, then roll two dice 3,600 times and compare. The program draws both side by side.

The idea. The exact probability counts equally likely pairs. A long simulation should land close to it, but not exactly on it.

Your tasks.

1. Fill exact with the probability of each sum, from the 36 pairs.
2. Fill simulated with the share of the rolls that gave each sum.
3. Set biggest_gap to the largest difference between the two, for any sum.