numbers = [12, 5, 11, 7]

x = int(input("Type an integer please: "))

# option 1 - use in
if x in numbers:
    print("That is one of my numbers")
else:
    print("Not one of my numbers")

# option 2 - use exception handling
try:
    i = numbers.index(x)
    print("that is one of my numbers")
except ValueError:
    print("Not one of my numbers")