import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; class test { public static void main(String[] args) throws IOException { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringBuilder sb = new StringBuilder(br.readLine()); int l = sb.length(); for(int i=l-1; i>=1; i--){ if ((l-i)%3==0) sb.insert(i,","); } System.out.println(sb); } }