#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0;i<n;i++)
#define repl(i,l,r) for(ll i=(l);i<(r);i++)
#define per(i,n) for(ll i=(n)-1;i>=0;i--)
#define perl(i,r,l) for(ll i=r-1;i>=l;i--)
#define fi first
#define se second
#define pb push_back
#define ins insert
#define pqueue(x) priority_queue<x,vector<x>,greater<x>>
#define all(x) (x).begin(),(x).end()
#define CST(x) cout<<fixed<<setprecision(x)
#define vtpl(x,y,z) vector<tuple<x,y,z>>
#define rev(x) reverse(x);
using ll=long long;
using vl=vector<ll>;
using vvl=vector<vector<ll>>;
using pl=pair<ll,ll>;
using vpl=vector<pl>;
using vvpl=vector<vpl>;
const ll MOD=1000000007;
const ll MOD9=998244353;
const int inf=1e9+10;
const ll INF=4e18;
const ll dy[9]={0,-1,0,1,1,1,-1,-1,0};
const ll dx[9]={-1,0,1,0,1,-1,1,-1,0};
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
ll n;
ll calc(vector<string> g){
    ll ret=0;
    rep(i,n){
        ll p=false;
        rep(j,2){
            bool ok=true;
            for(int s=j;s<j+n-1;s++)if(g[i][s]=='#')ok=false;
            p|=ok;
        }
        if(p)ret++;
    }
    return ret;
}
ll ncalc(vector<string> g){
    ll ans=0;
    chmax(ans,calc(g));
    rep(j,n){
        rep(i,2){
            bool ok=true;
            for(int s=i;s<i+n-1;s++)if(g[s][j]=='#')ok=false;
            if(ok){
                for(int s=i;s<i+n-1;s++)g[s][j]='#';
                chmax(ans,calc(g)+1);
                for(int s=i;s<i+n-1;s++)g[s][j]='.';
            }
        }
    }
    return ans;
}

int main(){
    cin >> n;
    vector<string> g(n);rep(i,n)cin >> g[i];
    ll ans=ncalc(g);
    vector<string> ng(n);
    rep(i,n){
        rep(j,n){
            ng[i]+=g[j][i];
        }
    }
    chmax(ans,ncalc(ng));
    cout << ans << endl;
}