How to know if your input is unique and doesn't have duplicates?

Question

The underlined sentences are what I'm having trouble adding in my code, I do know how to typecast numbers, but I don't know when in my code to do it.

gamblers = input().split()
winnings = 0
winnums =  ('10','11','8','1','5','20')
lim = len(gamblers)

for num in gamblers:
    if num in winnums:
        winnings+=100
if lim == 7:
    if winnings > 0:
        print(f"{gamblers[0]} won {winnings} pesos!")
    if winnings == 0:
        print (f"{gamblers[0]} won nothing!")
else:
    print("Should be 6 numbers")