import java.util.*;
class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    int n=in.nextInt();
    int s=in.nextInt();
    if(s>=n)
      System.out.print("unsafe");
    else
       System.out.print("safe");
  }
} import java.util.*; util.* java class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    int n=in.nextInt();
    int s=in.nextInt();
    if(s>=n)
      System.out.print("unsafe");
    else
       System.out.print("safe");
  }
} Main public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    int n=in.nextInt();
    int s=in.nextInt();
    if(s>=n)
      System.out.print("unsafe");
    else
       System.out.print("safe");
  } main {
    Scanner in=new Scanner(System.in);
    int n=in.nextInt();
    int s=in.nextInt();
    if(s>=n)
      System.out.print("unsafe");
    else
       System.out.print("safe");
  } Scanner in=new Scanner(System.in); in new Scanner(System.in) int n=in.nextInt(); n in.nextInt() in.nextInt in int s=in.nextInt(); s in.nextInt() in.nextInt in if(s>=n)
      System.out.print("unsafe");
    else
       System.out.print("safe"); s>=n s n System.out.print("unsafe") System.out.print System.out System System.out "unsafe" System.out.print("safe") System.out.print System.out System System.out "safe" String args[] args
import java.util.*;
class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    int n=in.nextInt();
    int s=in.nextInt();
    if(s>=n)
      System.out.print("unsafe");
    else
       System.out.print("safe");
  }
}