import math
theList = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]

print("Think of a number between 1 and 20")
print()
print("I guarantee I can guess your number in 5 guesses or fewer")
print()
input("Press Enter to let me start guessing your number")
found = False
guesses = 0

while found == False:
    guess = theList[math.ceil(len(theList)/2)-1]
    print()
    print("I guess",guess)
    check = input("Am I right? (y/n) ").upper()
    guesses = guesses + 1
    if check == "Y":
        found = True
    else:
        check = input("Do I need to guess Higher (H) or Lower (L)? ").upper()
        if check == "H":
            print("I need to guess higher")
            start = guess + 1
            end = theList[len(theList) - 1]
        elif check == "L":
            print("I need to guess lower")
            start = theList[0]
            end = guess - 1
        theList.clear()
        for i in range(start, end + 1):
            theList.append(i)
    if len(theList) == 1:
        guess = theList[math.ceil(len(theList)/2)-1]
        print("The number is", guess)
        found = True
        guesses = guesses + 1
print()
print("I got it in", guesses, "guesses")