import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    }
} Main public static void main(String[] args) {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    } main {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    } int S S W; W Scanner sc = new Scanner(System.in); sc new Scanner(System.in) S = sc.nextInt() S sc.nextInt() sc.nextInt sc W = sc.nextInt() W sc.nextInt() sc.nextInt sc int check = S > W ? 1 : 0; check S > W ? 1 : 0 S > W S W 1 0 switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        } check case 1: 1 case 1: System.out.println("safe") System.out.println System.out System System.out "safe" break; case 0: 0 case 0: 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) {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    }
} public class Main {
    public static void main(String[] args) {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int S, W;
        Scanner sc = new Scanner(System.in);
        S = sc.nextInt();
        W = sc.nextInt();
        int check = S > W ? 1 : 0;
        switch (check)
        {
            case 1:
                System.out.println("safe");
                break;
            case 0:
                System.out.println("unsafe");
        }
    }
}
