"use strict";
function Main(input) {
    let at = input.split("\n").map((v) => v - 0);
    let k = at[5];
    for (let n = 0; n < 4; n++) {
        for (let m = n+1; m < 5; m++) {
            let d = at[m] - at[n];
            if (d > k) {
                console.log(':(');
                return;
            }
        }
    }
    console.log('Yay!');
}
if (typeof window === 'undefined') Main(require("fs").readFileSync("/dev/stdin", "utf8"));
