import java.util.*; public class Main { static HashSet<String> set; static boolean is_boin (char a){ if(a=='a'||a=='i'||a=='u'||a=='e'||a=='o') return true; return false; } static boolean check(String a){ for(int i=0;i<a.length()-1;i++){ if(!is_boin(a.charAt(i)) && !is_boin(a.charAt(i+1))){ return false; } } return true; } static char[] moji = {'i','n','a','b','a','m','e','g','u','r','u'};//11moji static void func(String now,int used){ if(Integer.bitCount(used)==11){ if(!set.contains(now) && is_boin(now.charAt(10))){ System.out.println(now); System.exit(0); }else{ return; } } for(int i=0;i<11;i++){ if((used >> i & 1) == 0){ if( ((used>>2&1)==0 && (used>>4&1)>0 ) || ((used>>8&1)==0 && (used>>10&1)>0)) continue; if((used>>0&1)>0 && (used>>2&1)>0 &&(used>>4&1)>0 && (used>>6&1)>0 && (used>>8&1)>0 && (used>>10&1)>0) continue; if(!check(now+moji[i])) continue; used+=1<<i; func(now+moji[i], used); used-=1<<i; } } } public static void main(String[] args) { Scanner sc = new Scanner(System.in); int N = sc.nextInt(); set = new HashSet<>(); for(int i=0;i<N;i++)set.add(sc.next()); func("", 0); System.out.println("NO"); } }