def find_tts(prices):
    """Returns a list containing the buy day, sell day and resulting profit - finds the best days on which to buy and sell."""
    buyday = 0
    sellday = 0
    profit = 0
    for x in range(len(prices)):
        for y in range(x+1, len(prices)):
            if prices[x] < prices [y]:
                if prices[y] - prices[x] > profit:
                    profit = prices[y] - prices[x]
                    buyday = x
                    sellday = y
    return [buyday, sellday, profit]