import std.stdio;
import std.conv;
import std.array;

void main()
{
    int a = readln.split[0].to!int;
    int b = readln.split[0].to!int;
    int c = readln.split[0].to!int;
    int d = readln.split[0].to!int;
    int e = readln.split[0].to!int;
    int k = readln.split[0].to!int;

    if (e - a <= k){
        writeln("Yay!");
    } else {
        writeln(":(");
    }
}

