fn is_prime(num: u64) -> bool {
    let prime: bool = true;
    match num {
        0..=1 => false,
        2 => true,
        num if num % 2 == 0 => false,
        _ => {
            for i in (3..=((num as f64).sqrt() as u64)).step_by(2) {
                if num % i == 0 {
                    return false;
                }
            }
            prime
        }
    }
}

fn main() {
    let mut increment: u64 = 1;
    let mut total: u64 = 0;

    while increment < 2000000 {
        if is_prime(increment) {
            total += increment;
        }
        increment += 1
    }

    println!("{:?}", total);
}