x = -10
if x > -10 and x < 10:
    print("x has one digit")
else:
    print("x has more than one digit")

###
    
grade = 0
if grade >= 90:
    print("A")
elif grade >= 80:
    print("B")
elif grade >= 70:
    print("C")
elif grade >= 60:
    print("D")
else:
    print("R")

###
    
def double(x):
    return x + 2 # adding instead of multiplying

assert(double(3) == 6) # 6 is the intended result