def F2(ret):
    output = []
    for i in ret:
        if i not in output:
            output.append(i)
    print(output)


def F3(ret):
    output = [] # ahoj
    output2 = [] # jja
    output3 = []
    for i in ret:
        if i not in output:
            output.append(i)
        else:
            output2.append(i)
    for j in output:
        if j not in output2:
            output3.append(j)
    print(output3)