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