import java.io.*;
import java.util.*;


public class Main{
    static long [][] memo;
    static long [] pow = new long[33];
    static ArrayList <Integer> [] graph;
    static Integer [] d;
    static int [] dist;
    static boolean[][] visited;
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    }
    public static void bfs(int source, int i, int g)
    {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    }
    public static long solve(long n){
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    }
    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;
    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    //--------------------------------------------------------
} import java.io.*; io.* java import java.util.*; util.* java public class Main{
    static long [][] memo;
    static long [] pow = new long[33];
    static ArrayList <Integer> [] graph;
    static Integer [] d;
    static int [] dist;
    static boolean[][] visited;
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    }
    public static void bfs(int source, int i, int g)
    {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    }
    public static long solve(long n){
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    }
    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;
    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    //--------------------------------------------------------
} Main static long [][] memo; memo static long [] pow = new long[33]; pow new long[33] 33 static ArrayList <Integer> [] graph; graph static Integer [] d; d static int [] dist; dist static boolean[][] visited; visited //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out; out public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    } main {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    } MyScanner sc = new MyScanner(); sc new MyScanner() out = new PrintWriter(new BufferedOutputStream(System.out)) out new PrintWriter(new BufferedOutputStream(System.out)) long MOD = 1000000007; MOD 1000000007 int t = 1; t 1 while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        } t -- > 0 t -- t 0 {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        } int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc if(n <= m)
            out.println("unsafe");
            else
                out.println("safe"); n <= m n m out.println("unsafe") out.println out "unsafe" out.println("safe") out.println out "safe" out.close() out.close out String[] args args public static void bfs(int source, int i, int g)
    {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    } bfs {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    } if(visited[i][g]) return; visited[i][g] visited[i] visited i g return; visited[i][g] = true visited[i][g] visited[i] visited i g true if(g == 0) graph[source].add(i); g == 0 g 0 graph[source].add(i) graph[source].add graph[source] graph source i if(dist[i] <= g) bfs(source, i - 1, g - dist[i]); dist[i] <= g dist[i] dist i g bfs(source, i - 1, g - dist[i]) bfs source i - 1 i 1 g - dist[i] g dist[i] dist i if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]); dist[i + 1] <= g dist[i + 1] dist i + 1 i 1 g bfs(source, i + 1, g - dist[i + 1]) bfs source i + 1 i 1 g - dist[i + 1] g dist[i + 1] dist i + 1 i 1 int source source int i i int g g public static long solve(long n){
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    } solve {
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    } for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i]; int i = 1; int i = 1; i 1 i < 33 i 33 i ++ i ++ i if(n % pow[i] == 0)
                return n / pow[i]; if(n % pow[i] == 0)
                return n / pow[i]; n % pow[i] == 0 n % pow[i] n pow[i] pow i 0 return n / pow[i]; n / pow[i] n pow[i] pow i return -1; -1 1 long n n public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    } MyScanner BufferedReader br; br StringTokenizer st; st public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        } MyScanner {
            br = new BufferedReader(new InputStreamReader(System.in));
        } br = new BufferedReader(new InputStreamReader(System.in)) br new BufferedReader(new InputStreamReader(System.in)) String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } next {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        } while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } st == null || !st.hasMoreElements() st == null st null !st.hasMoreElements() st.hasMoreElements() st.hasMoreElements st {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            } try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } IOException e {
                    e.printStackTrace();
                } e.printStackTrace() e.printStackTrace e {
                    st = new StringTokenizer(br.readLine());
                } st = new StringTokenizer(br.readLine()) st new StringTokenizer(br.readLine()) return st.nextToken(); st.nextToken() st.nextToken st int nextInt() {
            return Integer.parseInt(next());
        } nextInt {
            return Integer.parseInt(next());
        } return Integer.parseInt(next()); Integer.parseInt(next()) Integer.parseInt Integer next() next long nextLong() {
            return Long.parseLong(next());
        } nextLong {
            return Long.parseLong(next());
        } return Long.parseLong(next()); Long.parseLong(next()) Long.parseLong Long next() next double nextDouble() {
            return Double.parseDouble(next());
        } nextDouble {
            return Double.parseDouble(next());
        } return Double.parseDouble(next()); Double.parseDouble(next()) Double.parseDouble Double next() next String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        } nextLine {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        } String str = ""; str "" try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } IOException e {
                e.printStackTrace();
            } e.printStackTrace() e.printStackTrace e {
                str = br.readLine();
            } str = br.readLine() str br.readLine() br.readLine br return str; str public class Main{
    static long [][] memo;
    static long [] pow = new long[33];
    static ArrayList <Integer> [] graph;
    static Integer [] d;
    static int [] dist;
    static boolean[][] visited;
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    }
    public static void bfs(int source, int i, int g)
    {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    }
    public static long solve(long n){
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    }
    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;
    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    //--------------------------------------------------------
} public class Main{
    static long [][] memo;
    static long [] pow = new long[33];
    static ArrayList <Integer> [] graph;
    static Integer [] d;
    static int [] dist;
    static boolean[][] visited;
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    }
    public static void bfs(int source, int i, int g)
    {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    }
    public static long solve(long n){
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    }
    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;
    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    //--------------------------------------------------------
} Main
import java.io.*;
import java.util.*;


public class Main{
    static long [][] memo;
    static long [] pow = new long[33];
    static ArrayList <Integer> [] graph;
    static Integer [] d;
    static int [] dist;
    static boolean[][] visited;
    public static void main(String[] args) {
        MyScanner sc = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        // Start writing your solution here. -------------------------------------
        long MOD = 1000000007;
        //int t = sc.nextInt();
        int t = 1;
        while(t -- > 0)
        {
            int n = sc.nextInt();
            int m = sc.nextInt();
            //int k = sc.nextInt();
            if(n <= m)
            out.println("unsafe");
            else
                out.println("safe");
        }
        out.close();
    }
    public static void bfs(int source, int i, int g)
    {
        if(visited[i][g]) return;
        visited[i][g] = true;
        if(g == 0) graph[source].add(i);

        if(dist[i] <= g) bfs(source, i - 1, g - dist[i]);
        if(dist[i + 1] <= g) bfs(source, i + 1, g - dist[i + 1]);
    }
    public static long solve(long n){
        for(int i = 1; i < 33; i ++)
            if(n % pow[i] == 0)
                return n / pow[i];
        return -1;
    }
    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;
    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt() {
            return Integer.parseInt(next());
        }
        long nextLong() {
            return Long.parseLong(next());
        }
        double nextDouble() {
            return Double.parseDouble(next());
        }
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    //--------------------------------------------------------
}
