fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut a = String::new();
    std::io::stdin().read_line(&mut a).ok();
    let a: Vec<usize> = a.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let calc = |x: usize| x * (x + 1) / 2;
    let mut result = calc(n);
    let mut avals = vec![];
    let mut idx = 0usize;
    for i in 1..n {
        if a[idx] != a[i] {
            if a[idx] == 1 {
                avals.push(i-idx);
            }
            idx = i;
        }
    }
    if a[idx] == 1 {
        avals.push(n - idx);
    }
    for &v in avals.iter() {
        result -= calc(v);
    }
    println!("{}", result);
}