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).

Input Specification:

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.

Output Specification:

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.

Sample Input:

-1000000 9

Sample Output:

-999,991

#include <cstdio>
int main(){
	int a,b,c;
	scanf("%d%d",&a,&b);
	c=a+b;
	if(c<0){
		printf("-");
		c=-c;
	}
	int num[10],len=0;
    do{
    	num[len++]=c%10;
    	c/=10;
    }while(c);
    for(int i=len-1;i>=0;i--){
    	printf("%d",num[i]);
    	if(i%3==0&&i!=0)
    	  printf(",");
    }
}