import java.io.*;

class Main
{
    public static void main(String args[])throws Exception
    {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        String s[]=bu.readLine().split(" ");
        int sh=Integer.parseInt(s[0]),w=Integer.parseInt(s[1]);
        if(sh<=w) System.out.print("unsafe");
        else System.out.print("safe");
    }
} import java.io.*; io.* java class Main
{
    public static void main(String args[])throws Exception
    {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        String s[]=bu.readLine().split(" ");
        int sh=Integer.parseInt(s[0]),w=Integer.parseInt(s[1]);
        if(sh<=w) System.out.print("unsafe");
        else System.out.print("safe");
    }
} Main public static void main(String args[])throws Exception
    {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        String s[]=bu.readLine().split(" ");
        int sh=Integer.parseInt(s[0]),w=Integer.parseInt(s[1]);
        if(sh<=w) System.out.print("unsafe");
        else System.out.print("safe");
    } main {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        String s[]=bu.readLine().split(" ");
        int sh=Integer.parseInt(s[0]),w=Integer.parseInt(s[1]);
        if(sh<=w) System.out.print("unsafe");
        else System.out.print("safe");
    } BufferedReader bu=new BufferedReader(new InputStreamReader(System.in)); bu new BufferedReader(new InputStreamReader(System.in)) String s[]=bu.readLine().split(" "); s bu.readLine().split(" ") bu.readLine().split bu.readLine() bu.readLine bu " " int sh=Integer.parseInt(s[0]) sh Integer.parseInt(s[0]) Integer.parseInt Integer s[0] s 0 w=Integer.parseInt(s[1]); w Integer.parseInt(s[1]) Integer.parseInt Integer s[1] s 1 if(sh<=w) System.out.print("unsafe");
        else System.out.print("safe"); sh<=w sh w 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.io.*;

class Main
{
    public static void main(String args[])throws Exception
    {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        String s[]=bu.readLine().split(" ");
        int sh=Integer.parseInt(s[0]),w=Integer.parseInt(s[1]);
        if(sh<=w) System.out.print("unsafe");
        else System.out.print("safe");
    }
}
