fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

// 標準入力から一行を読み取り、空白文字で分割し、各要素を指定の型に変換する関数
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>().split_whitespace()
        .map(|e| e.parse().ok().unwrap()).collect()
}

fn read_vec2<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}

fn main() {
    let v = read_vec::<i16>();
    let (a, b, c) = (v[0], v[1], v[2]);

    let money = a + 10 * b;
    let howManyCoins = a + b;
    let deltaCoins = howManyCoins - c;

    if deltaCoins < -9 {
        println!("Impossible");
        return
    }else if deltaCoins >= -9 && deltaCoins < 0{
        println!("{}", 10 + deltaCoins);
    }else if deltaCoins == 0 {
        println!("{}", 0);
    }else if deltaCoins > 0{
        for i in 0..deltaCoins{
            let j = deltaCoins - i;
            if i <= b && j <= a{
                println!("{}",i*10+j);
                return
            }
        }
        println!("Impossible");
    }
}