fn is_odd(number: &i32) -> bool {
    number % 2 != 0
}


fn fairRations(B: &[i32]) -> String {
    let mut b_vec = B.to_vec();
    let mut counter = 0;
    for i in 0..(b_vec.len() - 1) {
        if is_odd(&b_vec[i]) {
            b_vec[i + 1] += 1;
            counter += 2;
        }
    }
    
    if b_vec.last().unwrap() % 2 == 0 && b_vec.len() > 2 {
        return counter.to_string() 
    }
    return "NO".to_string()
}