string = "I am 20 years old. I live in New York in United States of America."
stop = ["am", "old", "in", "of"]
z = list(set(string.split()) - set(stop))
print(z)
c3RyaW5nID0gIkkgYW0gMjAgeWVhcnMgb2xkLiBJIGxpdmUgaW4gTmV3IFlvcmsgaW4gVW5pdGVkIFN0YXRlcyBvZiBBbWVyaWNhLiIKc3RvcCA9IFsiYW0iLCAib2xkIiwgImluIiwgIm9mIl0KeiA9IGxpc3Qoc2V0KHN0cmluZy5zcGxpdCgpKSAtIHNldChzdG9wKSkKcHJpbnQoeik=
['United', '20', 'I', 'live', 'years', 'States', 'America.', 'York', 'New', 'old.']