"use strict";
    
const main = arg => {
    arg = arg.split("\n");

    const k = parseInt(arg.slice(5, arg.length));
    const antennas = arg.slice(0, arg.length - 1).map(n=>parseInt(n));
    
    console.log(antennas[4] - antennas[0] > k ? ":(" : "Yay!");
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));
