A1001

 1 #include<iostream>
 2 #include<stdio.h>
 3 using namespace std;
 4 int main(){
 5     int a,b;
 6     scanf("%d%d",&a,&b);
 7     int sum=a+b;
 8     if(sum<0){
 9         printf("-"); 
10         sum=-sum;
11     }
12     if(sum<1000)
13       printf("%d",sum);
14     if(sum>=1000&&sum<1000000) 
15       printf("%d,%03d",sum/1000,sum%1000);
16     if(sum>=1000000&&sum<10000000) 
17       printf("%d,%03d,%03d",sum/1000000,(sum%1000000)/1000,sum%1000);
18     return 0;
19 }