Напомена: ово је незванична копија задатака. Као таква, не гарантује се да ће овај сајт бити одржаван, и немојте се изненадити ако са њега задаци одједном нестану.

The postman arrived with a mysterious letter from an unknown sender. The strangest thing about it is that the message was sent in early 2023, but still somehow arrived in mid-December 2022. Upon opening the letter, you found a video recording of the final match of the World Cup, which is yet to be played between Argentina and France. The letter also contained a “spoiled” final score for the game. You decided to watch this odd video from the future.

During the half-time, you looked at the current result \(x:y\) and remembered the predicted final result \(a:b\) from the letter. You started wondering: is it possible to predict which team would be the next to score a goal, assuming that the result in the letter was correct? This problem asks you to answer this question.

Input format

The first line of standard input contains two natural numbers \(a\) and \(b\), the “spoiled” result.

The second line of standard input contains two integers \(x\) and \(y\), the half-time score.

Output format

Your program should print one line to the standard output:

Sample 1

Input

1 2
1 0

Output

drugi

Sample 2

Input

1 1
1 1

Output

nijedan

Sample 3

Input

4 4
3 2

Output

?

Explanation

In the first testcase, the first team already scored all of their goals for the game, but the second team didn’t. The only possible continuation is \(1:0 \to 1:1 \to 1:2\). Therefore, the second team has to be the next to score.

In the second testcase, all goals happen before the half-time, so there will be no further goals.

In the third testcase, there are multiple continuations and it is not possible to predict the next goal:

Constraints

Testcases are split into three disjoint groups: