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

Example Input: Problem: a rectangular plot measuring 90 metres by 50 metres is to be enclosed by wire fencing . if the poles of the fence are kept 10 metres apart , how many poles will be needed ?
Example Output: 28

Example Input: Problem: a can do a piece of work in 80 days . he works at it for 10 days b alone finishes the remaining work in 42 days . in how much time will a and b working together , finish the work ?
Example Output: 30

Example Input: Problem: find the ones digit of 73 ^ 340
Example Output:
3