Problem:
Score : 100 points

Problem Statement

Takahashi has a strong stomach. He never gets a stomachache from eating something whose "best-by" date is at most X days earlier.
He gets a stomachache if the "best-by" date of the food is X+1 or more days earlier, though.

Other than that, he finds the food delicious if he eats it not later than the "best-by" date. Otherwise, he does not find it delicious.

Takahashi bought some food A days before the "best-by" date, and ate it B days after he bought it.

Write a program that outputs delicious if he found it delicious, safe if he did not found it delicious but did not get a stomachache either, and dangerous if he got a stomachache.

Constraints

1 ≤ X,A,B ≤ 10^9

Input

Input is given from Standard Input in the following format:

X A B

Output

Print delicious if Takahashi found the food delicious; print safe if he neither found it delicious nor got a stomachache; print dangerous if he got a stomachache.

Sample Input 1

4 3 6

Sample Output 1

safe

He ate the food three days after the "best-by" date. It was not delicious or harmful for him.

Sample Input 2

6 5 1

Sample Output 2

delicious

He ate the food by the "best-by" date. It was delicious for him.

Sample Input 3

3 7 12

Sample Output 3

dangerous

He ate the food five days after the "best-by" date. It was harmful for him.

Solution in Pascal (FPC 2.6.2) (judge verdict: Runtime Error)

const fi='trained.inp';
      fo='trained.out';
var a,dau:array[0..100005] of longint;
    n,d:longint;
    
procedure mo;
begin
    assign(input,fi);
    reset(input);
    assign(output,fo);
    rewrite(output);
end;

procedure nhap;
var i:longint;
begin
    readln(n);
    for i:=1 to n do
        readln(a[i]);
end;

procedure xuly;
var i:longint;
begin
    d:=0;   i:=1;
    repeat
        dau[i]:=1;
        i:=a[i];
        inc(d);
    until (dau[2]=1)or(dau[i]=1);
end;

procedure xuat;
begin
    if dau[2]=1 then
        writeln(d-1)
    else
        writeln('-1');
end;

begin
    
    nhap;
    xuly;
    xuat;
end.