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 Rust (1.15.1) (judge verdict: Accepted)

use std::str::FromStr;

#[derive(Default)]
struct Conf {
    antennas: [u8; 5],
    k: u8,
}

impl Conf {
    fn new() -> Conf {
        Conf::default()
    }
}

fn parse_line(buf: &mut String) -> u8 {
    buf.clear();
    std::io::stdin().read_line(buf).unwrap();
    let buf = buf.trim();
    u8::from_str(buf).unwrap()
}

fn parse() -> Conf {
    let mut conf  = Conf::new();
    let mut buf = String::new();

    for i in 0..5 {
        conf.antennas[i] = parse_line(&mut buf);
    }
    conf.k = parse_line(&mut buf);

    conf
}

fn main() {
    let conf = parse();

    let min = conf.antennas.iter().min().unwrap();
    let max = conf.antennas.iter().max().unwrap();

    if conf.k < (max - min) {
        println!(":(");
    } else {
        println!("Yay!");
    }

}