Python Counting Vowels

I have started on a program to count vowels and have seemed to be getting nowhere. I need to count vowels from a string and then display the vowels. I need to do this by storing the number of occurrences in variables. Like this :

    a = 0

    b = 0
    ....

    then print the lowest.

Current code (its not that much ):

string = str(input("please input a string:  "))
edit= ''.join(string)



print(edit)

I have tried a number of methods just by my self and don't seem to get anywhere.