#include<bits/stdc++.h> 
using namespace std;
bool isVowel(char c){
    c = tolower(c);
    return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
}

int main() {
    string s;
    cin >> s;

    int len = s.length();
    if (len % 2 != 0 || len > 1000) return 1;

    int mid = len / 2;
    int count1 = 0, count2 = 0;

    for (int i = 0; i < mid; i++) {
        if (isVowel(s[i])) count1++;
    }
    for (int i = mid; i < len; i++) {
        if (isVowel(s[i])) count2++;
    }

    if (count1 == count2) {
        std::cout << "YES";
    } else {
        std::cout << "NO";
    }

    return 0;
}