#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Yukicoder №784 「,（カンマ）」 ★
// https://yukicoder.me/problems/no/784
// ***********************
// for debug
#define DEBUGs
#define	YUKICODER
// -----------


#ifdef YUKICODER
#define gc(c)	do{c = getchar_unlocked();}while(0)
#define pc(c)	putchar_unlocked(c)
	extern char getchar_unlocked(void);
	extern void putchar_unlocked(char c);
#else
#define gc(c)	do{c = getchar();}while(0)
#define pc(c)	putchar(c)
#endif
void out(int n) { // 整数の表示（出力）
	int i;
	char b[30];

	if (!n) pc('0');
	else {
		if (n < 0) pc('-'), n = -n;
		i = 0; while (n) b[i++] = n % 10 + '0', n /= 10;
		while (i--) pc(b[i]);
	}
	pc('\n');
}
#define NOP do{}while(0)
#ifdef DEBUG
#define TRACE(...)	do{printf(__VA_ARGS__);fflush(stdout);}while(0)
#define TRACECR	do{putchar_unlocked('\n');fflush(stdout);}while(0)
#else
#define TRACE(...)	NOP
#define TRACECR	NOP
#endif
#define errmes(...)	do{fprintf(stderr,__VA_ARGS__);}while(0)
#define	mypc(d)	putchar_unlocked((int)(d))
#define PRINCR mypc('\n')
#define NOCR(strig)	do{char *p;p=strchr(strig,'\n');if(p)*p='\0';}while(0)
// for stdio
#define GETLINE(str)	do{char *p;fgets(str,sizeof(str),stdin);p=strchr(str,'\n');if(p)*p='\0';}while(0)
#define	GETINTS(a,b) {char s[34];int *ap=a;REP(i,b){GETWORD(s);*ap++=atoi(s);}}
#define SWAP(type,a,b)	do{type _c;_c=a;a=b;b=_c;}while(0)
#define MAX(a,b)	((a)>(b)?(a):(b))
#define REP(a,b) for(int a=0;a<(int)(b);++a)
#define REP1(a,b) for(int a=1;a<=(int)(b);++a)
#define Possible(a) 	   printf("%s",((a)?"Possible":"Impossible"))
#define possible(a) 	   printf("%s",((a)?"possible":"impossible"))
// The out-of-date function
#define	asctime(...)	asctime_s(...)
#define	ctime(...)		ctime_s(...)
#define	str_len(a)	mystr_len(a)
#define mystr_len(str)	mystr_len_lim(str,9999)
static char *GETWORD(char* str) {char c;char *cp;cp=&str[0];gc(c);while(c!=EOF){if((c==' ')||(c=='\n'))break;*cp++=c;gc(c);}*cp='\0';return &str[0];}
static int GETLINEINT(void) {char s[34];GETLINE(s);return atoi(s);}
static int GETWORDINT(void) {char s[34];GETWORD(s);return atoi(s);}
static long GETWORDLONG(void) {char s[34];GETWORD(s);return atol(s);}
static int maxi(int a,int b){if((a)>(b)){return a;}return b;}
static long maxl(long a,long b){if(a>b){return a;}return b;}
static int mystr_len_lim(char *str,int lim){int i=0;do{if(str[i]=='\0')break;i++;}while(i<lim);return i;}
// *********************
typedef struct DEFINT2 {
	int	x;
	int	y;
} TINT2;


// *********************
// *********************
char *COMMA(char *ostr, int	limit, char *istr ) {
	int	lnk = -1;
	char	*ip;
	char	*op;

	op = &ostr[limit-1];
	ip = &istr[ str_len( istr ) -1 ];
	*(op)-- = '\0';
	// start
	while( ip >= istr ) {
		if( ++lnk >= 3 ) {
			*(op)-- = ',';
			lnk = 0;
		}
		*(op)-- = *(ip)--;
	}
	return ++(op);
}
// *********************
int main( void ) {
	char	str[1537];
	char	ostr[1537];
	char	*op;

	GETLINE(str);
	op = COMMA(ostr,1537,str);
	printf("%s\n",op);
}