x=100
z=0
y=""
r=""
while y!="yes":
    g=((x+z)/2)
    y=input("Enter 'yes' if your guess is" + g)
    if y=="yes":
        print("Good job!")
    else:
        r=input("Is your number higher or lower?")
        if r == "higher":
            z=g
        else r == "lower":
            x=g