import java.io.*;
import java.util.*;
public class Main{

    private static void solver(InputReader sc, PrintWriter out) throws Exception {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    }
    private static int gcd(int a, int b){
        if(b==0)
            return a;
        return gcd(b, a%b);
    }
    public static void main(String[] args) throws Exception {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    }
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        }
    }
}
class Pair  implements  Comparable<Pair>{
    int x;
    int y;
    int z;

    Pair(int x, int y, int z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair pair = (Pair) o;
        return x == pair.x &&
                y == pair.y;
    }

    @Override
    public int hashCode() {
        return Objects.hash(x, y, z);
    }

    @Override
    public int compareTo(Pair o) {
        return this.x-o.x;
    }
} import java.io.*; io.* java import java.util.*; util.* java public class Main{

    private static void solver(InputReader sc, PrintWriter out) throws Exception {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    }
    private static int gcd(int a, int b){
        if(b==0)
            return a;
        return gcd(b, a%b);
    }
    public static void main(String[] args) throws Exception {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    }
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        }
    }
} Main private static void solver(InputReader sc, PrintWriter out) throws Exception {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    } solver {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    } int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc out.println(n<=m ? "unsafe" : "safe" ) out.println out n<=m ? "unsafe" : "safe" n<=m n m "unsafe" "safe" InputReader sc sc PrintWriter out out private static int gcd(int a, int b){
        if(b==0)
            return a;
        return gcd(b, a%b);
    } gcd {
        if(b==0)
            return a;
        return gcd(b, a%b);
    } if(b==0)
            return a; b==0 b 0 return a; a return gcd(b, a%b); gcd(b, a%b) gcd b a%b a b int a a int b b public static void main(String[] args) throws Exception {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    } main {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out InputReader in = new InputReader(inputStream); in new InputReader(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) solver(in,out) solver in out out.close() out.close out String[] args args static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        }
    } InputReader public BufferedReader reader; reader public StringTokenizer tokenizer; tokenizer public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        } InputReader {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        } reader = new BufferedReader(new InputStreamReader(stream), 32768) reader new BufferedReader(new InputStreamReader(stream), 32768) tokenizer = null tokenizer null InputStream stream stream public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        } next {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        } while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            } tokenizer == null || !tokenizer.hasMoreTokens() tokenizer == null tokenizer null !tokenizer.hasMoreTokens() tokenizer.hasMoreTokens() tokenizer.hasMoreTokens tokenizer {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            } try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                } IOException e {
                    throw new RuntimeException(e);
                } throw new RuntimeException(e); new RuntimeException(e) {
                    tokenizer = new StringTokenizer(reader.readLine());
                } tokenizer = new StringTokenizer(reader.readLine()) tokenizer new StringTokenizer(reader.readLine()) return tokenizer.nextToken(); tokenizer.nextToken() tokenizer.nextToken tokenizer public int nextInt() {
            return Integer.parseInt(next());
        } nextInt {
            return Integer.parseInt(next());
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next public long nextLong() {
            return Long.parseLong(next());
        } nextLong {
            return Long.parseLong(next());
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        } readIntArray {
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        } int arr[] = new int[n]; arr new int[n] n for(int i=0;i<n;i++) arr[i] = nextInt(); int i=0; int i=0; i 0 i<n i n i++ i++ i arr[i] = nextInt(); arr[i] = nextInt() arr[i] arr i nextInt() nextInt return arr; arr int n n class Pair  implements  Comparable<Pair>{
    int x;
    int y;
    int z;

    Pair(int x, int y, int z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair pair = (Pair) o;
        return x == pair.x &&
                y == pair.y;
    }

    @Override
    public int hashCode() {
        return Objects.hash(x, y, z);
    }

    @Override
    public int compareTo(Pair o) {
        return this.x-o.x;
    }
} Pair int x; x int y; y int z; z Pair(int x, int y, int z) {
        this.x = x;
        this.y = y;
        this.z = z;
    } Pair {
        this.x = x;
        this.y = y;
        this.z = z;
    } this.x = x this.x this this.x x this.y = y this.y this this.y y this.z = z this.z this this.z z int x x int y y int z z @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair pair = (Pair) o;
        return x == pair.x &&
                y == pair.y;
    } equals {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair pair = (Pair) o;
        return x == pair.x &&
                y == pair.y;
    } if (this == o) return true; this == o this o return true; true if (o == null || getClass() != o.getClass()) return false; o == null || getClass() != o.getClass() o == null o null getClass() != o.getClass() getClass() getClass o.getClass() o.getClass o return false; false Pair pair = (Pair) o; pair (Pair) o return x == pair.x &&
                y == pair.y; x == pair.x &&
                y == pair.y x == pair.x x pair.x pair pair.x y == pair.y y pair.y pair pair.y Object o o @Override
    public int hashCode() {
        return Objects.hash(x, y, z);
    } hashCode {
        return Objects.hash(x, y, z);
    } return Objects.hash(x, y, z); Objects.hash(x, y, z) Objects.hash Objects x y z @Override
    public int compareTo(Pair o) {
        return this.x-o.x;
    } compareTo {
        return this.x-o.x;
    } return this.x-o.x; this.x-o.x this.x this this.x o.x o o.x Pair o o Comparable public class Main{

    private static void solver(InputReader sc, PrintWriter out) throws Exception {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    }
    private static int gcd(int a, int b){
        if(b==0)
            return a;
        return gcd(b, a%b);
    }
    public static void main(String[] args) throws Exception {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    }
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        }
    }
} public class Main{

    private static void solver(InputReader sc, PrintWriter out) throws Exception {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    }
    private static int gcd(int a, int b){
        if(b==0)
            return a;
        return gcd(b, a%b);
    }
    public static void main(String[] args) throws Exception {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    }
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        }
    }
} Main
import java.io.*;
import java.util.*;
public class Main{

    private static void solver(InputReader sc, PrintWriter out) throws Exception {
      int n = sc.nextInt();
     int m = sc.nextInt();
     out.println(n<=m ? "unsafe" : "safe" );

    }
    private static int gcd(int a, int b){
        if(b==0)
            return a;
        return gcd(b, a%b);
    }
    public static void main(String[] args) throws Exception {
        // long start =  System.nanoTime();
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solver(in,out);
        out.close();


    }
    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }
        public long nextLong() {
            return Long.parseLong(next());
        }
        public int[] readIntArray(int n){
            int arr[] = new int[n];
            for(int i=0;i<n;i++) arr[i] = nextInt();
            return arr;
        }
    }
}
class Pair  implements  Comparable<Pair>{
    int x;
    int y;
    int z;

    Pair(int x, int y, int z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Pair pair = (Pair) o;
        return x == pair.x &&
                y == pair.y;
    }

    @Override
    public int hashCode() {
        return Objects.hash(x, y, z);
    }

    @Override
    public int compareTo(Pair o) {
        return this.x-o.x;
    }
}