import java.util.Scanner;
//int[] date=new int[2];
public class Main {
int i,o,sum,h,s,e,u,ty,yu,ui,n,num,qw;
double m,t,r,j,k,f,d,g,w;
static double l;
String b,c,z,x,v,a,q;
Scanner scan =new Scanner(System.in);
//入力
	public void input() {	
	
	}
	//演算
	public void compute() {
	
		}
//出力
	public void output() {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		}
	public static void main(String [ ] args) {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		}
	} import java.util.Scanner; Scanner java.util public class Main {
int i,o,sum,h,s,e,u,ty,yu,ui,n,num,qw;
double m,t,r,j,k,f,d,g,w;
static double l;
String b,c,z,x,v,a,q;
Scanner scan =new Scanner(System.in);
//入力
	public void input() {	
	
	}
	//演算
	public void compute() {
	
		}
//出力
	public void output() {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		}
	public static void main(String [ ] args) {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		}
	} Main int i i o o sum sum h h s s e e u u ty ty yu yu ui ui n n num num qw; qw double m m t t r r j j k k f f d d g g w; w static double l; l String b b c c z z x x v v a a q; q Scanner scan =new Scanner(System.in); scan new Scanner(System.in) //入力
	public void input() {	
	
	} input {	
	
	} //演算
	public void compute() {
	
		} compute {
	
		} //出力
	public void output() {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		} output {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		} int[] date=new int[2]; date new int[2] 2 for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	} o=0; o=0 o 0 o<2 o 2 o++ o++ o {
		date[o]=scan.nextInt();
	} {
		date[o]=scan.nextInt();
	} date[o]=scan.nextInt() date[o] date o scan.nextInt() scan.nextInt scan if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	} date[0]<=date[1] date[0] date 0 date[1] date 1 {
		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" public static void main(String [ ] args) {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		} main {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		} Main p = new  Main (); p new  Main () p.input() p.input p p.compute() p.compute p p.output() p.output p String [ ] args args public class Main {
int i,o,sum,h,s,e,u,ty,yu,ui,n,num,qw;
double m,t,r,j,k,f,d,g,w;
static double l;
String b,c,z,x,v,a,q;
Scanner scan =new Scanner(System.in);
//入力
	public void input() {	
	
	}
	//演算
	public void compute() {
	
		}
//出力
	public void output() {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		}
	public static void main(String [ ] args) {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		}
	} public class Main {
int i,o,sum,h,s,e,u,ty,yu,ui,n,num,qw;
double m,t,r,j,k,f,d,g,w;
static double l;
String b,c,z,x,v,a,q;
Scanner scan =new Scanner(System.in);
//入力
	public void input() {	
	
	}
	//演算
	public void compute() {
	
		}
//出力
	public void output() {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		}
	public static void main(String [ ] args) {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		}
	} Main
import java.util.Scanner;
//int[] date=new int[2];
public class Main {
int i,o,sum,h,s,e,u,ty,yu,ui,n,num,qw;
double m,t,r,j,k,f,d,g,w;
static double l;
String b,c,z,x,v,a,q;
Scanner scan =new Scanner(System.in);
//入力
	public void input() {	
	
	}
	//演算
	public void compute() {
	
		}
//出力
	public void output() {
	int[] date=new int[2];
	for(o=0;o<2;o++) {
		date[o]=scan.nextInt();
	}
	if(date[0]<=date[1]) {
		System.out.println("unsafe");
	}else {
		System.out.println("safe");
	}
		}
	public static void main(String [ ] args) {
		Main p = new  Main ();
		p.input();
		p.compute();
		p.output();
		}
	}