import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	} main {
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int seep = sc.nextInt(); seep sc.nextInt() sc.nextInt sc int wolf = sc.nextInt(); wolf sc.nextInt() sc.nextInt sc System.out.println(wolf >= seep ? "unsafe" : "safe ") System.out.println System.out System System.out wolf >= seep ? "unsafe" : "safe " wolf >= seep wolf seep "unsafe" "safe " String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	}
} Main
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		int seep = sc.nextInt();
		int wolf = sc.nextInt();
		// 出力
		System.out.println(wolf >= seep ? "unsafe" : "safe ");
	}
}