import java.util.*;
public class Main {

    public static boolean isPrime(int x) {
        if(x == 1) {
            return false;
        }
        for(int i = 2 ; i * i <= x ; i++) {
            if(x % i == 0) {
                return false;
            }
        }
        return true;
    }
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()) {
            int x = sc.nextInt();
            int y = sc.nextInt();
            boolean isSu = true;
            if(x == 0 && y == 0) {
                return;
            }
            for(int i = x ; i <= y ; i++) {
                int re = i * i + i + 41;
                if(!isPrime(re)) {
                    isSu = false;
                    break;
                }
            }
            if(isSu) {
                System.out.println("OK");
            } else {
                System.out.println("Sorry");
            }
        }
    }
}