Format a string into phone number format

Format a string into phone number format using a java program.

I have given a number of string in normal format so change it to contact number format.

Input  : 12327364883
output : 123-273-648-83




public class NumberFormat {

public static void main(String[] args) {
Scanner scn = new Scanner(System.in);
String str= scn.nextLine();
System.out.println(getNumber(str));

}

public static String getNumber(String s){
String number="";

String str = s.replace(" ","").replace("--", "").replace("-", "");
String[] st = str.split("");
if((st.length%3) >=2){
for(int i=0;i<st.length;i++){
if(((i+1)%3 != 0)){
number+=st[i];
}else{
if(i != st.length-1){
number+=st[i]+"-";
}else{
number+=st[i];
}
}
}
return number;
}else{
for(int i=0;i<st.length;i++){
if(((i+1)%3 != 0)){
number+=st[i];
}else{
if(i == st.length-2){
number+="-"+st[i];
}else if(i != st.length-1){
number+=st[i]+"-";
}else{
number+=st[i];
}
}
}
}
return number;
}


}