Bulls and Cows is a classic number guessing game where the objective is to guess a hidden four-digit number. Each digit must be between 0 and 9, and no digit can be repeated. - 〇 indicates a digit is correct and in the correct position. - △ indicates a digit is correct but in the wrong position. To play, use the keyboard to input your guesses. Press number keys to input digits and the space bar to delete. Use arrow keys or clicks to select the grid cell for input. Scroll the mouse wheel to review previous guesses. Once you are confident with your guess, press Enter or the submit button to make your guess. Try to guess the number in as few attempts as possible, testing your memory and logical skills!