24K Magic - Boolean logic- only challenge 7 not working what should i do to improve my code ?

purity = float(input()) if purity >= 75.0 and purity < 83.3 : print("18K") elif purity >= 83.3 and purity < 91.7 : print("20K") elif purity >= 91.7 and purity < 99.9 : print("22K") elif purity == 99.99: print("24K")