import java.util.Scanner;
class Main{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
String a = scan.nextLine();
String b = scan.nextLine();
if (a.length()%2==0){
System.out.print(b);
int j=20;
for(int i=0; i<((j-2-a.length())/2); i++){
System.out.print(".");
}
System.out.print(a);
for(int i=0; i<((j-2-a.length())/2); i++){
System.out.print(".");}
System.out.print(b);
}
else
{
  System.out.print(b);
int j=20;
for(int i=0; i<((j-2-a.length())/2); i++){
System.out.print(".");
}
System.out.print(a);
for(int i=0; i<((j-2-a.length())/2); i++){
System.out.print(".");}
System.out.print("?");
System.out.print(b);
}
}}

Loops
1. 
public class Main{
    public static void main(String[] args) {
for(int i=0; i<=5; i++){System.out.print(i+"\t");};
System.out.println(" ");
for(int k=5; k>=0; k--){System.out.print(k+"\t");};
}}
2.
public class Main{
    public static void main(String[] args) {
for(int i=1; i<=9; i=i+2){
System.out.print(i+" ");};
}}
3.
import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
      Scanner scan = new Scanner(System.in);
int a =scan.nextInt();
int b =scan.nextInt();
int c=a+b;
int d=a*b;
System.out.print(c);
System.out.println(" ");
System.out.print(d);
  }}

4.

5.

6.

import java.util.Scanner;

class Main {

  public static void main(String[] args) {

    int m;

    int n;

  Scanner scan = new Scanner(System.in);

  int a = scan.nextInt();

  m=a/10;

  n=a%10;

System.out.println (n+" "+m);

}}

7.

public class Main{

    public static void main(String[] args) {

        char c;

        for(c = 'A'; c <= 'Z'; ++c)

            System.out.print(c + " ");

            System.out.println(" ");

        for(c = 'a'; c <= 'z'; ++c)

            System.out.print(c + " ");

    }

}

8.

9.

import java.util.Scanner;

class Main {

  public static void main(String[] args) {

  Scanner scan = new Scanner(System.in);

  int a = scan.nextInt();

  int b = scan.nextInt();

if (a==b){System.out.println("numbers are the same");}

if (a>b){System.out.println(b);} else {System.out.println(a);}

}}