#include<stdio.h>
int main(){
  int i;
  char n[30];
  int c;
  scanf("%s",n);
  for(c=0;n[c]!='\0';c++);

  if(c%3==1){
    printf("%c",n[0]);
    for(i=1;i<c;i+=3){
      printf(",%c%c%c",n[i],n[i+1],n[i+2]);
    }
    printf("\n");
  }else if(c%3==2){
    printf("%c%c",n[0],n[1]);
    for(i=2;i<c;i+=3){
      printf(",%c%c%c",n[i],n[i+1],n[i+2]);
    }
    printf("\n");
  }else if(c%3==0){
      printf("%c%c%c",n[0],n[1],n[2]);
    for(i=3;i<c;i+=3){
      printf(",%c%c%c",n[i],n[i+1],n[i+2]);
    }
    printf("\n");
  }

  return 0;
}