import java.util.Scanner;
import java.util.Arrays;
public class Pangram
{
    public static void main(String[] args)
    {
        Scanner sc=new Scanner(System.in);
        String x=sc.nextLine().toLowerCase();
        int[] y=new int[26];
        char z[]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
        char[] a=x.toCharArray();
        Arrays.sort(a);
        int b;
        for(b=0;b<26;b++)
            y[b]=0;
        if(x.length()<26)
            System.out.println("NO");
        else
        {
            for(b=0;b<26;b++)
                for(int c=0;c<a.length;c++)
                    if(z[b]==a[c])
                        y[b]++;
            for(b=0;b<26;b++)
            {
                if(y[b]>0)
                    continue;
                else
                {
                    System.out.println("NO");
                    break;
                }
            }
            if(b==26)
                System.out.println("YES");
        }
    }
}