import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		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);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		System.out.println("unsafe");
    	} else {
    		System.out.println("safe");
    	}
    	
        scan.close();
    }
} Main public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		System.out.println("unsafe");
    	} else {
    		System.out.println("safe");
    	}
    	
        scan.close();
    } main {
        Scanner scan = new Scanner(System.in);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		System.out.println("unsafe");
    	} else {
    		System.out.println("safe");
    	}
    	
        scan.close();
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) double s = scan.nextDouble(); s scan.nextDouble() scan.nextDouble scan double w = scan.nextDouble(); w scan.nextDouble() scan.nextDouble scan if(s <= w){
    		System.out.println("unsafe");
    	} else {
    		System.out.println("safe");
    	} s <= w s w {
    		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);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		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);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		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);
        double s = scan.nextDouble();
    	double w = scan.nextDouble();
 
    	if(s <= w){
    		System.out.println("unsafe");
    	} else {
    		System.out.println("safe");
    	}
    	
        scan.close();
    }
}