String Task Codeforces Problem - https://codeforces.com/problemset/problem/118/A - c++17

Question

https://codeforces.com/problemset/problem/118/A
my code:
#include<iostream>
#include<string.h>
using namespace std;
int main()
{
string str;
cin >> str;
for(int i=0; i<sizeof(str); i++)
{
if(str[i] >= 'A' && str[i] <= 'Z')
str[i]+=32;
{
if(str[i] >= 'a' && str[i] <= 'z' && str[i] != 'a' && str[i] != 'e' && str[i] != 'i' && str[i] != 'o' && str[i] != 'u' && str[i] != 'A' && str[i] != 'E' && str[i] != 'I' && str[i] != 'O' && str[i] != 'U')
cout << "." << str[i];
}
}
return 0;
}
Where is the problem in this code because it gives wrong when I submit?
I am not seeing any problem, could anyone help me to detect?

Answer 1

In the question they have included 'y' as a vowel too. I changed some other stuff too (like, use i<str.size() not i<sizeof(str) ), try the following code it will get accepted :
int main()
{
string str;
cin >> str;
for(int i=0; i<str.size(); i++)
{
char temp;
temp = str[i];
if(temp >= 'A' && temp <= 'Z')
temp = tolower(temp);
if(temp != 'a' && temp != 'e' && temp != 'i' && temp != 'o' && temp != 'u' && temp != 'y')
cout << "." << temp;
}
return 0;
}