C++ :

#include <iostream>
#include <string>
using namespace std;
int main() {
    string str;
    do {
        getline(cin, str);
        if (!str.empty()) {
            int vowelCount = 0;
            for (char ch : str) {
                ch = tolower(ch);
                if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
                    ++vowelCount;
                }
            }
            cout << vowelCount << endl;
        }
    } while (!str.empty());
    return 0;
}