def main():
    arr = {10,20.5,"Hello",10}
    
    print(type(arr))
    print(arr)
    
    print(len(arr))
    
    for value in arr:
        print(value)
        
    if "Hello" in arr:
        print("Hello is there")
        
    arr.add(20)
    print(arr)
    
    #arr.remove(120)
    #print(arr)
    
    arr.discard(120)
    print(arr)
        
if __name__ == "__main__":
    main()