Vowels of a String

// Vowels of a String
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    bool a=false;
    string s;
    cin>>s;
    int n=s.length();
    for(int i=0;i<n;i++)
    {
        if(s[i]=='a'||s[i]=='e'||s[i]=='i'||s[i]=='o'||s[i]=='u')
        {
            a=true;
        }
        else if(s[i]=='A'||s[i]=='E'||s[i]=='I'||s[i]=='O'||s[i]=='U')
        {
            a=true;
        }
        else
        {
            a=false;
            break;
        }
    }
    if(a)
    {
        cout<<"Yes";
    }
    else
    {
        cout<<"No";
    }
    return 0;
}