Let's play tic-tac-toe together. You should play well and try to win. Follow all of the instructions below.

After the instructions, we can start playing. Whoever is player X will go first.

I will declare who is X and who is O.

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{{{ BEGIN INSTRUCTIONS }}}
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## Board

Format for an empty board:

```
. . .
. . .
. . .
```

Numeric labels for each board position:

123
456
789

------------------------------------------

## Game-Over-Check

Process for checking if the game is over:

- Write out the board position numbers and values for every possible 3-in-a-row
- Check each of the written combinations and see if there is a valid 3-in-a-row
- Announce the game is over if there is a valid 3-in-a-row

- Rows:
    - R1 - pos 1,2,3: Val Val Val
    - R2 - pos 4,5,6: Val Val Val
    - R3 - pos 7,8,9: Val Val Val
- Columns:
    - C1 - pos 1,4,7: Val Val Val
    - C2 - pos 2,5,8: Val Val Val
    - C3 - pos 3,6,9: Val Val Val
- Diagonals:
    - D1 - pos 1,5,9: Val Val Val
    - D2 - pos 3,5,7: Val Val Val

------------------------------------------

## Example 1 of running Game-Over-Check

Board:

```
X . O
X X .
O O .
```

Run Game-Over-Check

- Rows:
    - R1 - pos 1,2,3: X . O
    - R2 - pos 4,5,6: X X .
    - R3 - pos 7,8,9: O O .
- Columns:
    - C1 - pos 1,4,7: X X O
    - C2 - pos 2,5,8: . X O
    - C3 - pos 3,6,9: O . .
- Diagonals:
    - D1 - pos 1,5,9: X X .
    - D2 - pos 3,5,7: O X O

Result: No 3-in-a-row, game is ongoing.

------------------------------------------

## Example 2 of running Game-Over-Check

Board:

```
. . X
. O .
O X .
```


Run GOC:

- Rows:
    - R1 - pos 1,2,3: . . X
    - R2 - pos 4,5,6: . O .
    - R3 - pos 7,8,9: O X .
- Columns:
    - C1 - pos 1,4,7: . . O
    - C2 - pos 2,5,8: . O X
    - C3 - pos 3,6,9: X . .
- Diagonals:
    - D1 - pos 1,5,9: . O .
    - D2 - pos 3,5,7: X O O

Result: No 3-in-a-row, game is ongoing.

------------------------------------------

## Example 3 of running Game-Over-Check

Board:

```
X . O
X O .
X . O
```

Run Game-Over-Check:

- Rows:
    - R1 - pos 1,2,3: X . O
    - R2 - pos 4,5,6: X O .
    - R3 - pos 7,8,9: X . O
- Columns:
    - C1 - pos 1,4,7: X X X
    - C2 - pos 2,5,8: . O .
    - C3 - pos 3,6,9: O . O
- Diagonals:
    - D1 - pos 1,5,9: X O O
    - D2 - pos 3,5,7: O O X

Result: Column 1 has a 3 X's in a row! Player X wins.

------------------------------------------

## Example 4 of running Game-Over-Check

Board:

```
X X O
. O X
O . X
```

Run Game-Over-Check:

- Rows:
    - R1 - pos 1,2,3: X X O
    - R2 - pos 4,5,6: . O X
    - R3 - pos 7,8,9: O . X
- Columns:
    - C1 - pos 1,4,7: X . O
    - C2 - pos 2,5,8: X O .
    - C3 - pos 3,6,9: O X X
- Diagonals:
    - D1 - pos 1,5,9: X O X
    - D2 - pos 3,5,7: O O O

Result: Diagonal 2, top-right to bottom left, has a 3 O's in a row! Player O wins.

------------------------------------------

## Play Instructions

- We take turns. I'll make a move, then you make a move, then back to me. And so on.

On your turn:
- After my move, before you make a move, run Game-Over-Check using the updated board
- Then make your move.
- Display the updated board
- Run Game-Over-Check again using the updated board

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{{{ END INSTRUCTIONS }}}
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Let's start the game :)

I'll be player X, you will play O.

I play an X at position 5. Your turn.