Problem:
Score : 100 points

Problem Statement

There are S sheep and W wolves.

If the number of wolves is greater than or equal to that of sheep, the wolves will attack the sheep.

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Constraints

1 \leq S \leq 100

1 \leq W \leq 100

Input

Input is given from Standard Input in the following format:

S W

Output

If the wolves will attack the sheep, print unsafe; otherwise, print safe.

Sample Input 1

4 5

Sample Output 1

unsafe

There are four sheep and five wolves. The number of wolves is not less than that of sheep, so they will attack them.

Sample Input 2

100 2

Sample Output 2

safe

Many a sheep drive away two wolves.

Sample Input 3

10 10

Sample Output 3

unsafe

Solution in Pascal (FPC 3.0.4) (judge verdict: Wrong Answer)

program main;
type
    arraytype = array[1..200000] of string[10];
var
    i, n, count : longint;
    A : arraytype;

procedure Quicksort(var A : arraytype; left, right : integer);
var
   i, j : integer;
   pivot, temp : string;
begin
    i := left; 
    j := right;
    pivot := A[(left + right) div 2];
    while i <= j do begin
        while A[i] < pivot do 
            i := i + 1;
        while A[j] > pivot do 
            j := j - 1;
        if i <= j then begin 
            temp := A[i];
            A[i] := A[j];
            A[j] := temp;
            i := i + 1;
            j := j - 1;
        end;
    end;
    if left < j
        then Quicksort(A, left, j);
    if i < right 
        then Quicksort(A, i, right);
end;

begin
    //read
    readln(n);
    for i := 1 to n do 
        readln(A[i]);
    
    //sort
    Quicksort(A, 1, n);

    //count
    count := 1;
    for i := 2 to n do
       if A[i] <> A[i-1]
           then count := count + 1;
    writeln(count);
end.