s1 = "object oriented"

print("ted" in s1)    # Does "ted" exists in s1 ?

print("eject" in s1)   # Does "eject" exists in s1 ?

print("orion" not in s1)   # Doesn't "orion" exists in s1 ?

print("en" not in s1)   # Doesn't "en" exists in s1 ?