import java.util.Scanner;

public class Coin 
{
private final int HEADS = 0;
private final int TAILS = 1;
private int face;
boolean locked = false;
Scanner scan = new Scanner(System.in);
//-----------------------------------------------------------------
// Sets up the coin by flipping it initially.
//-----------------------------------------------------------------
public Coin ()
{
flip();
}
//-----------------------------------------------------------------
// Flips the coin by randomly choosing a face value.
//-----------------------------------------------------------------

public int setKey(int key)
{ if (locked == false)
{System.out.println("Please enter the integer key you would like to set.");
key = scan.nextInt();
System.out.println("The key has been set.");
}

return key;
}

public void lock(int key)
{ 
if (locked == false);
{
System.out.println("Please enter the key to lock this class.");
int keyattempt = scan.nextInt();
if (keyattempt == key) 
{
locked = true;
}
else
{ 
locked = false;
System.out.println("You entered the key incorrectly. The class remains unlocked.");
}
}
}

private void unlock(int key)
{ 
while (locked ==true)
{
System.out.println("Please enter your key to unlock the class.");
int keyattempt2 = scan.nextInt();
if (keyattempt2 == key)
locked = false;
else
{ 
locked = true;
System.out.println("You entered the key incorrectly. The class remains locked.");
}
}
}


boolean locked()
{
if (locked == true)
return true;
else
return false;
}

public void flip ()
{ if (locked == false)
{
face = (int) (Math.random() * 2);
}

}
//-----------------------------------------------------------------
// Returns true if the current face of the coin is heads.
//-----------------------------------------------------------------
public boolean isHeads ()
{ 
if (locked == false)
{
return (face == HEADS);
}
return locked;

}
//-----------------------------------------------------------------
// Returns the current face of the coin as a string.
//-----------------------------------------------------------------
public String toString()
{ if (locked == false)
{
String faceName;
if (face == HEADS)
faceName = "Heads";
else
faceName = "Tails";
return faceName;

}
return null;

}

}