#!/bin/bash
awk 'BEGIN{FS=""}{fg1=NF%3
if(NF<4)
        {print $0}
else
        {for(i=1;i<=NF;i++)
                {if(i%3==fg1&&i!=NF)
                        {printf "%s,",$i}
                else
                        {printf "%s",$i}}
        print ""}}' nowcoder