#include <stdio.h>
#include <string.h>

int main(void){
	char n[100] = "a";
	scanf("%s",n);
	int count = 3 - (int)strlen(n)%3;
	if(count == 3){
		count = 0;
	}

	for(int i = 0 ; i < (int)strlen(n);i++){
		printf("%c",n[i]);
		count++;
		if(count == 3 && i != (int)strlen(n)-1){
			printf(",");
			count = 0;
		}
	}
}