fn run() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let it = s.trim().split_whitespace();
    let mut sum = 0u64;
    for (i, s) in it.enumerate() {
        if i % 2 == 1 {
            continue;
        }
        let a: u64 = s.parse().unwrap();
        sum += a;
    }
    if sum % 2 == 0 {
        println!(":-)");
    } else {
        println!(":-(");
    }
}

fn main() {
    run();
}