def makeMove(board, chests, x, y):
        # Change the board data structure with a sonar device character. Remove treasure chests from the chests list as they are found.
        # Return False if this is an invalid move.
        # Otherwise, return the string of the result of this move.
        smallestDistance = 100 # Any chest will be closer than 100.
        for cx, cy in chests: # For 'value 1' and 'value 2' in each index of the list
            # If each index didn't have two values, this wouldn't work.
            # This isn't a nested loop or anything.
            distance = math.sqrt((cx - x) * (cx - x) + (cy - y) * (cy - y))

            if distance < smallestDistance: # We want the closest treasure chest.
                smallestDistance = distance

        smallestDistance = round(smallestDistance)

        if smallestDistance == 0:
            # xy is directly on a treasure chest!
            chests.remove([x,y])
            return 'You have found a sunken treasure chest!'
        else:
            if smallestDistance < 10:
                board[x][y] = str(smallestDistance)
                return 'Treasure detected at a distance of %s from the sonar device' % (smallestDistance)
            else:
                board[x][y] = 'X'
                return 'Sonar did not detect anything. All treasure chests out of range.'