#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    int N; cin >> N;
    stack<pair<long long,long long>> st;
    long long answer = 0;
    for(int x=0; x<N; x++){
        string s; cin >> s;
        long long white = 0,black = 2*N;
        for(int i=0; i<2*N; i++) if(s.at(i) == '.') answer += i-white,white++;
        black -= white;
        if(black > N){
            long long b = black-N; 
            answer += b*(b-1)/2;
            while(st.size() && st.top().second > 0 && b){
                auto &[x2,w] = st.top();
                long long use = min(b,w);
                answer += use*(x-x2+1);
                w -= use,b -= use;
                if(w == 0) st.pop();
            }
            if(b) st.push({x,-b});
        }
        else if(white > N){
            long long w = white-N;
            answer += w*(w-1)/2;
            while(st.size() && st.top().second < 0 && w){
                auto &[x2,b] = st.top();
                long long use = min(-b,w);
                answer += use*(x-x2+1);
                w -= use,b += use;
                if(b == 0) st.pop(); 
            }
            if(w) st.push({x,w});
        }
    }
    cout << answer << endl;
}