The task is to generate the correct answer for a given math problem.

Input: Consider Input: Problem: a certain bacteria colony doubles in size every day for 25 days , at which point it reaches the limit of its habitat and can no longer grow . if two bacteria colonies start growing simultaneously , how many days will it take them to reach the habitat ' s limit ?

Output: 2

Input: Consider Input: Problem: a train passes a platform in 32 seconds . the same train passes a man standing on the platform in 20 seconds . if the speed of the train is 54 km / hr , the length of the platform is

Output: 180 meter

Input: Consider Input: Problem: what is the units digit of 17 ^ 83 13 ^ 82 11 ^ 67 ?
Output: 4