split string en mots et commencer par derniers mots

import java.util.*;
import java.io.*;
import java.math.*;

class Solution {

    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        String S = in.nextLine();
        int fin = S.length()-1;
        for(int i = S.length()-1; i >= 0; i--)
        {
            if(S.charAt(i) == ' ')
            {
                for(int j = i+1; j <= fin; j++)
                    System.out.print(S.charAt(j));
                System.out.print(" ");
                fin = i-1;
            }
            if(i == 0)
            {
                for(int j = i; j <= fin; j++)
                    System.out.print(S.charAt(j));
            }
        }
    }
}