## Description:

Your task is to Calculate a + b.

## Input:

Input contains multiple test cases. Each test case contains a pair of integers a and b, one pair of integers per line. A test case containing 0 0 terminates the input and this test case is not to be processed.

## Output:

For each pair of input integers a and b you should output the sum of a and b in one line, and with one line of output for each line in input.

## Sample Input:

1 5
10 20
0 0

## Sample Output:

6
30