use proconio::{input, marker::Chars};

fn main() {
    input! {
        n: usize,
        s: [Chars; n],
    }

    let calc = |l: usize, r: usize| r * r.saturating_sub(1) / 2 - l * l.saturating_sub(1) / 2;

    let mut ans = 0usize;
    let mut count = vec![];
    for s in &s {
        let mut cnt = 0usize;
        let mut sum = 0;
        for j in 0..2 * n {
            if s[j] == '.' {
                cnt += 1;
                sum += j;
            }
        }
        ans += sum - calc(0, cnt);
        count.push(cnt);
    }

    for i in 0..n {
        if count[i] == n {
            continue;
        }

        while count[i] > n {
            let j = (i..n).find(|&j| count[j] < n).unwrap();
            let c = (count[i] - n).min(n - count[j]);
            let cost = (j - i) * c + calc(count[i] - c, count[i]) - calc(count[j], count[j] + c);
            ans += cost;
            count[i] -= c;
            count[j] += c;
        }

        while count[i] < n {
            let j = (i..n).find(|&j| count[j] > n).unwrap();
            let c = (count[j] - n).min(n - count[i]);
            let cost = (j - i) * c + calc(count[j] - c, count[j]) - calc(count[i], count[i] + c);
            ans += cost;
            count[i] += c;
            count[j] -= c;
        }
    }

    println!("{ans}");
}