Problem:
﻿Score: 100 points

Problem Statement

In AtCoder city, there are five antennas standing in a straight line. They are called Antenna A, B, C, D and E from west to east, and their coordinates are a, b, c, d and e, respectively.

Two antennas can communicate directly if the distance between them is k or less, and they cannot if the distance is greater than k.

Determine if there exists a pair of antennas that cannot communicate directly.

Here, assume that the distance between two antennas at coordinates p and q (p < q) is q - p.

Constraints

a, b, c, d, e and k are integers between 0 and 123 (inclusive).

a < b < c < d < e

Input

Input is given from Standard Input in the following format:

a
b
c
d
e
k

Output

Print :( if there exists a pair of antennas that cannot communicate directly, and print Yay! if there is no such pair.

Sample Input 1

1
2
4
8
9
15

Sample Output 1

Yay!

In this case, there is no pair of antennas that cannot communicate directly, because:

the distance between A and B is 2 - 1 = 1

the distance between A and C is 4 - 1 = 3

the distance between A and D is 8 - 1 = 7

the distance between A and E is 9 - 1 = 8

the distance between B and C is 4 - 2 = 2

the distance between B and D is 8 - 2 = 6

the distance between B and E is 9 - 2 = 7

the distance between C and D is 8 - 4 = 4

the distance between C and E is 9 - 4 = 5

the distance between D and E is 9 - 8 = 1

and none of them is greater than 15. Thus, the correct output is Yay!.

Sample Input 2

15
18
26
35
36
18

Sample Output 2

:(

In this case, the distance between antennas A and D is 35 - 15 = 20 and exceeds 18, so they cannot communicate directly.
Thus, the correct output is :(.

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;

public class Answer {
    private static readonly string TextOK = "Yay!";
    private static readonly string TextNG = ":(";
  
    private static void Main(string[] args) {
        var numberOfLines = 5;
        var inputs = new List<string>();
        
        for (int lineIndex = 0; lineIndex < numberOfLines; lineIndex++) {
            inputs.Add(Console.ReadLine().Trim());
        }

        var inputLastLine = Console.ReadLine().Trim();
        
        Console.WriteLine(GetAnswer(inputs, inputLastLine));
    }
  
	private static string GetAnswer(List<string> inputs, string inputLastLine) {
        var distance = CalculateDistance(int.Parse(inputs[0]), int.Parse(inputs[inputs.Count - 1]));

        if (!IsDistanceOK(distance, int.Parse(inputLastLine))) {
            return TextNG;
        }

        return TextOK;
    }

    private static int CalculateDistance(int a, int b) => Math.Abs(a - b);
    private static bool IsDistanceOK(int distance, int standard) => distance <= standard;
}