import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.StringTokenizer;
 
public class Main{
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  }
} import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io import java.io.IOException; IOException java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main{
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  }
} Main public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  } main {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  } BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); in new BufferedReader(new InputStreamReader(System.in)) StringTokenizer st = new StringTokenizer(in.readLine()); st new StringTokenizer(in.readLine()) int S = Integer.parseInt(st.nextToken()); S Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st int W = Integer.parseInt(st.nextToken()); W Integer.parseInt(st.nextToken()) Integer.parseInt Integer st.nextToken() st.nextToken st System.out.println(S>W?"safe":"unsafe") System.out.println System.out System System.out S>W?"safe":"unsafe" S>W S W "safe" "unsafe" String[] args args public class Main{
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  }
} public class Main{
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  }
} Main
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.StringTokenizer;
 
public class Main{
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer(in.readLine());
    int S = Integer.parseInt(st.nextToken());
    int W = Integer.parseInt(st.nextToken());
    System.out.println(S>W?"safe":"unsafe");
  }
}