# -*- coding: utf-8 -*-
"""
Created on Sat Oct  1 21:08:17 2022

@author: Roman
"""

alph = 'eyuoai'
s = input("Введите строку латиницей: ")
s = s.lower()
N = len(s)
summ = 0

for c in alph:
    summ += s.count(c)

print("{:.2%}".format(summ / N))