Problem in Python (Try, Finally and Except)

I'm trying to get an accurate age but this doesn't work it gives me errors and sometimes repeats itself. I've been trying to get it to work for hours. But I can't figure it out, I think the problem is in finally. I tried except but it just gives me errors. How should I fix it?

end04 = False                      
while not end04:
    Age = input("Age: ")
    try:
        int(Age)
        end04 = True
    finally:
        if Age[-1:] == 'w':
            Age.replace('w','')
            int(Age)
            Age /= 52
            end04 = True
        elif Age[-1:] == 'm':
            Age.replace('m', '')
            int(Age)
            Age /= 12
            end04 = True
        else:
            end04 = False
            print("Only enter m or w after number or just number")

if I put finally It just repeats saying "Only enter m or w after a number or just number"

If I put except it gives an error (When I enter 3m)

int(Age) ValueError: invalid literal for int() with base 10: '3m'