## Description:

Calculate a + b.

## Input:

The input will consist of a series of pairs of integers a and b,separated by a space, one pair of integers per line. A line containing 0 0 terminates the input and this line 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

3 3

0 0

## Sample Output:

6

6

## Note:

本题由旧版NOJ导入，来源：HDUOJ