// Program 78: Snowball String

import java.util.*;
class SnowballString {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine().trim().replaceAll("[.?!]$", "");
        String[] words = s.split("\\s+");
        boolean ok = true;
        for (int i = 1; i < words.length; i++) {
            if (words[i].length() != words[i - 1].length() + 1) {
                ok = false;
            }
    }
System.out.println(ok ? "SNOWBALL STRING" : "NOT A SNOWBALL STRING");
}
}