'use strict';
function Main(input) {
    input = input.split("\n");
    let tmp = input[0].split(" ");
    //console.log(input);
    for(let i=0;i<5;i++){
        for(let j = i;j<5;j++){
            //console.log(`A:${input[i]} vs B:${input[j]} = abs:${input[i]-input[j]}`)

            if (Math.abs(input[i]-input[j])>input[5]){
                console.log(":(");
                return;
            }
        }
    }
    console.log("Yay!");
    return;
}
/*
Main(`1
2
4
8
9
15`);
*/
Main(require("fs").readFileSync("/dev/stdin", "utf8"));