import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    } main {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String[] str = sc.nextLine().split(" "); str sc.nextLine().split(" ") sc.nextLine().split sc.nextLine() sc.nextLine sc " " if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        } Integer.parseInt(str[0]) <= Integer.parseInt(str[1]) Integer.parseInt(str[0]) Integer.parseInt Integer str[0] str 0 Integer.parseInt(str[1]) Integer.parseInt Integer str[1] str 1 {
            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 public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String[] str = sc.nextLine().split(" ");
        if(Integer.parseInt(str[0]) <= Integer.parseInt(str[1])){
            System.out.print("unsafe");
        }else{
            System.out.print("safe");
        }
    }
}
