import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

void main() {
    int[] a;
    foreach (_; 0..5) a ~= readint;
    int k = readint;

    // 両端の差が k 以下か調べるだけでよい
    bool ans = a[$-1] - a[0] <= k;
    writeln(ans ? "Yay!" : ":(");
}
