import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int S = sc.nextInt(); S sc.nextInt() sc.nextInt sc int W = sc.nextInt(); W sc.nextInt() sc.nextInt sc String safety = null; safety null if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        } W >= S W S {
            safety = "unsafe";
        } safety = "unsafe" safety "unsafe" {
            safety = " safe";
        } safety = " safe" safety " safe" System.out.println(safety) System.out.println System.out System System.out safety String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();
        int W = sc.nextInt();
        
        String safety = null;
        
        if(W >= S){
            safety = "unsafe";
        } else {
            safety = " safe";
        }
        
        System.out.println(safety);
    }
}
