Under the given constraints, the answer can be expressed as:

\[ \dfrac{n(n+1)}{2}\cdot k\cdot100+\dfrac{k(k+1)}{2}\cdot n \]

• Time complexity is \(\mathcal{O}(1)\).
• Space complexity is \(\mathcal{O}(1)\).

use proconio::input;

fn main() {
    input! {
        n: usize,
        k: usize,
    }

    println!("{}", n * (n + 1) / 2 * k * 100 + k * (k + 1) / 2 * n);
}