def remove_vowels(document) -> str:
    return_list=[]
    for i in document:
        if i.lower() not in ['a', 'e', 'i', 'o', 'u', 'y']:
            return_list.append(i)
    return ''.join(return_list)

print(remove_vowels('a1e2i3u4y5AIEUYO'))  #12345