import java.util.Scanner;

class Main
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        if(b>=a)
        {
            System.out.print("unsafe");
        }
        else
        {
            System.out.print("safe");
        }

    }
} import java.util.Scanner; Scanner java.util class Main
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        if(b>=a)
        {
            System.out.print("unsafe");
        }
        else
        {
            System.out.print("safe");
        }

    }
} Main public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        if(b>=a)
        {
            System.out.print("unsafe");
        }
        else
        {
            System.out.print("safe");
        }

    } main {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        if(b>=a)
        {
            System.out.print("unsafe");
        }
        else
        {
            System.out.print("safe");
        }

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a = sc.nextInt(); a sc.nextInt() sc.nextInt sc int b = sc.nextInt(); b sc.nextInt() sc.nextInt sc if(b>=a)
        {
            System.out.print("unsafe");
        }
        else
        {
            System.out.print("safe");
        } b>=a b a {
            System.out.print("unsafe");
        } System.out.print("unsafe") System.out.print System.out System System.out "unsafe" {
            System.out.print("safe");
        } System.out.print("safe") System.out.print System.out System System.out "safe" String args[] args
import java.util.Scanner;

class Main
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();

        if(b>=a)
        {
            System.out.print("unsafe");
        }
        else
        {
            System.out.print("safe");
        }

    }
}