1001 A+B Format

Calculate a+b and output the sum in standard format – that is, the digits must be separated into groups of three by commas (unless there are less than four digits).（计算‎‎a+‎‎b‎‎以标准格式输出总和 ，也就是说，数字必须按逗号分成三组（除非少于四位数字）。）‎

Input Specification（输入规格）:

Each input file contains one test case. Each case contains a pair of integers a and b where −10 * *6 ≤a,b≤10 * *6​​ . The numbers are separated by a space.（每个输入文件包含一个测试用例。每个案例都包含一对整数‎a‎和‎‎B‎‎在哪里‎‎•‎‎1‎000000 ‎≤‎‎a‎‎，b‎‎≤‎‎1000000‎.数字由空格分隔。‎）

Output Specification（输出规格）:

For each test case, you should output the sum of a and b in one line. The sum must be written in the standard format.（对于每个测试用例，应输出‎a‎和‎‎B‎‎在一行。总和必须以标准格式写入。‎）

Sample Input（示例输入）:

-1000000 9

Sample Output（示例输出）:

-999,991

l1 = input().split()
a,b = int(l1[0]),int(l1[1])
print('{:,}'.format(a+b))