function Main(input) {
    input = input.split("\n").map(i => parseInt(i, 10))
 
    const limit = input.pop()
    
    const result = (input[4] - input[0] > limit) ?  ': (' : 'Yay!' 
    console.log(result)
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"))