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