import java.util.Scanner;
 
public class Main {
 
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
 
		int A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {
 
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
 
		int A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		}
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
 
		int A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		}
	} main {
		Scanner sc = new Scanner(System.in);
 
		int A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int A = sc.nextInt(); A sc.nextInt() sc.nextInt sc int B = sc.nextInt(); B sc.nextInt() sc.nextInt sc if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		} A - B > 0 A - B A B 0 {
			System.out.println("safe");
		} System.out.println("safe") System.out.println System.out System System.out "safe" {
			System.out.println("unsafe");
		} 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 A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			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 A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		}
	}
} Main
import java.util.Scanner;
 
public class Main {
 
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
 
		int A = sc.nextInt();
		int B = sc.nextInt();
		
		if (A - B > 0) {
			System.out.println("safe");
		} else {
			System.out.println("unsafe");
		}
	}
}