import java.util.Scanner;
import java.util.Arrays;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util import java.util.stream.*; stream.* java.util public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} Main public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    } main {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) Integer s = Integer.parseInt(scanner.next()); s Integer.parseInt(scanner.next()) Integer.parseInt Integer scanner.next() scanner.next scanner Integer w = Integer.parseInt(scanner.next()); w Integer.parseInt(scanner.next()) Integer.parseInt Integer scanner.next() scanner.next scanner if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        } w >= s w s {
            System.out.println("unsafe");
        } System.out.println("unsafe") System.out.println System.out System System.out "unsafe" {
            System.out.println("safe");
        } System.out.println("safe") System.out.println System.out System System.out "safe" String[] args args public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
} Main
import java.util.Scanner;
import java.util.Arrays;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) {
        //コード
        Scanner scanner = new Scanner(System.in);
        Integer s = Integer.parseInt(scanner.next());
        Integer w = Integer.parseInt(scanner.next());

        if(w >= s) {
            System.out.println("unsafe");
        } else {
            System.out.println("safe");
        }
    }
}
