View Code of Problem 101

#include<stdio.h>

#include<string.h>
int main(){
char a[100],b[100];
int i,j;
while(~scanf("%s",&a)) {
		int j=0;
		int count=0;
		for(i=strlen(a)-1;i>=0;i--){
			if(a[i]!=',')
			{
				if(count%3==0&&count!=0)
					b[j++]=',';
					
				b[j++]=a[i];
				count++;
			}
		}
	for(i=j-1;i>=0;i--){
		printf("%c",b[i]);
	}
	
	printf("\n");
	
}
	
	
	
	
	return 0;
}