import java.util.*;
import java.math.*;

public class Main {
    static final int MOD = 1_000_000_007; // 10^9+7
    // static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9
    static final int MAX = 10_000_000;
    static long[] fact = new long[100];
        public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    }
    
} import java.util.*; util.* java import java.math.*; math.* java public class Main {
    static final int MOD = 1_000_000_007; // 10^9+7
    // static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9
    static final int MAX = 10_000_000;
    static long[] fact = new long[100];
        public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    }
    
} Main static final int MOD = 1_000_000_007; // 10^9+7 MOD 1_000_000_007 // static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9 INF 1_000_000_000 static final int MAX = 10_000_000; MAX 10_000_000 static long[] fact = new long[100]; fact new long[100] 100 public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    } main {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            } n<=m n m {
                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 {
    static final int MOD = 1_000_000_007; // 10^9+7
    // static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9
    static final int MAX = 10_000_000;
    static long[] fact = new long[100];
        public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    }
    
} public class Main {
    static final int MOD = 1_000_000_007; // 10^9+7
    // static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9
    static final int MAX = 10_000_000;
    static long[] fact = new long[100];
        public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    }
    
} Main
import java.util.*;
import java.math.*;

public class Main {
    static final int MOD = 1_000_000_007; // 10^9+7
    // static final int MAX = 2_147_483_646; // intの最大値
    static final int INF = 1_000_000_000; // 10^9
    static final int MAX = 10_000_000;
    static long[] fact = new long[100];
        public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
            int n = sc.nextInt();
            int m = sc.nextInt();
            if(n<=m){
                System.out.println("unsafe");
            }else{
                System.out.println("safe");
            }
    }
    
}
