#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(ll i=a;i<b;i++)
#define rrep(i,a,b) for(ll i=a-1;i>=b;i--)
#define ll long long
#define ull unsigned ll
#define ld long double
#define bl __int128_t
#define fi first
#define se second
#define vel vector<ll>
#define vvel vector<vel>
#define pll pair<ll,ll>
#define vepll vector<pll>
#define vvepll vector<vepll>
#define ves vector<string>
#define vem vector<mint>
#define vvem vector<vem>
#define pmm pair<mint,mint>
#define bl __int128_t
#define cleout(i) cout<<fixed<<setprecision(i)
template<class T>using PQ=priority_queue<T,vector<T>,greater<T>>;
//               上  右 下 左
vector<int> di={-1, 0, 1, 0};
vector<int> dj={ 0, 1, 0,-1};

vector<int> dx={ 0, 1, 0,-1};
vector<int> dy={ 1, 0,-1, 0};


vector<int> ddx={ 1, 1, 1, 0, -1, -1, -1, 0 };
vector<int> ddy={ 1, 0, -1, -1, -1, 0, 1, 1 };

ll inf=1000000000000000000;//1e18
// LLONG_MAX

mt19937_64 rng((ull)chrono::steady_clock::now().time_since_epoch().count());

//[x^M]1/(1-x)^N=comb(N-1+M,M)



void _solve(){
    ll N;
    cin>>N;
    vvel a(N,vel(2*N));
    rep(i,0,N){
        string S;
        cin>>S;
        rep(j,0,2*N){
            if(S[j]=='#')a[i][j]=1;
        }
    }
    vel l(2*N);
    rep(i,0,N){
        rep(j,0,2*N){
            if(a[i][j]==0)l[j]++;
        }
    }
    ll ans=0;
    ll id=0;
    rep(i,0,N){
        ll cnt=0;
        while(id<2*N){
            if(l[id]==0){
                id++;
            }else{
                cnt++;
                ans+=abs(id-i);
                l[id]--;
            }
            if(cnt==N)break;
        }
    }
    id=0;
    vel r(N);
    rep(i,0,N){
        rep(j,0,2*N){
            if(a[i][j]==0)r[i]++;
        }
    }
    rep(i,0,N){
        ll cnt=0;
        while(id<2*N){
            if(r[id]==0){
                id++;
            }else{
                cnt++;
                ans+=abs(id-i);
                r[id]--;
            }
            if(cnt==N)break;
        }
    }
    cout<<ans<<"\n";
}


int main(){
    cin.tie(nullptr);
 	ios_base::sync_with_stdio(false);

    
    ll _;
    bool multitest=0;
    if(multitest)cin>>_;
    else _=1;
    rep(__,0,_){
        _solve();
    }
}