import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		 Scanner scan =new Scanner(System.in);
		int n, m;
		while (scan.hasNext()) {
			n = scan.nextInt();
			String c=scan.nextLine();
			//m = scan.nextInt();
			while(n!=0){
				n--;
				String s=scan.nextLine();
				int judge;
				if(s.matches("[a-z_A-Z][a-z_A-Z0-9]{0,}"))
						judge=1;
					else judge=0;
				
				if(judge==1)
					System.out.println("yes");
				else 
					System.out.println("no");
			}
			
		}
	}
}