import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    } main {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    } 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 if(s>w) System.out.println("safe");
        else System.out.println("unsafe"); s>w s w System.out.println("safe") System.out.println System.out System System.out "safe" System.out.println("unsafe") System.out.println System.out System System.out "unsafe" String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    }
} Main
import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner (System.in);
        int s = sc.nextInt();
        int w = sc.nextInt();
        if(s>w) System.out.println("safe");
        else System.out.println("unsafe");
    }
}