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

Example Input: Problem: if 1.5 cm of a pencil is purple , 0.5 cm of the remaining is black and the remaining 2 cm is blue , what is the total length of the pencil ?
Example Output: 4 cm

Example Input: Problem: a salt manufacturing company produced a total of 2000 tonnes of salt in january of a particular year . starting from february its production increased by 100 tonnes every month over the previous months until the end of the year . find its ave 66 rage daily production for that year ?
Example Output: 83

Example Input: Problem: find value for x from below equation ? x + 1 = - 3
Example Output:
- 4