

import java.util.Scanner;

public class Main{

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	}

} import java.util.Scanner; Scanner java.util public class Main{

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	}

} Main public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	} main {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String line = sc.nextLine(); line sc.nextLine() sc.nextLine sc String[] lines = line.split(" "); lines line.split(" ") line.split line " " Double S = Double.parseDouble(lines[0]); S Double.parseDouble(lines[0]) Double.parseDouble Double lines[0] lines 0 Double W = Double.parseDouble(lines[1]); W Double.parseDouble(lines[1]) Double.parseDouble Double lines[1] lines 1 if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		} W >= S W S {
			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" String[] args args public class Main{

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	}

} public class Main{

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	}

} Main


import java.util.Scanner;

public class Main{

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		String line = sc.nextLine();
		String[] lines = line.split(" ");
		Double S = Double.parseDouble(lines[0]);
		Double W = Double.parseDouble(lines[1]);

		if(W >= S) {
			System.out.println("unsafe");
		}
		else {
			System.out.println("safe");
		}
	}

}
