PLUS-SONGMAN

#include <bits/stdc++.h>

using namespace std;
using LINT = long long int;
using PII = pair<int,int>;

#define PB push_back
#define FI first
#define SE second
#define REP(i,n) for(int i=0;i<(n);++i)
#define FOR(i, a, b) for(int i=(a);i<(b);++i)

int t;

int n;
string grid[2007];
int dpu[2007][2007];
int dpb[2007][2007];
int dpl[2007][2007];
int dpr[2007][2007];

void process(){
    cin>>n;
    REP(i,n)cin>>grid[i];
    memset(dpu, 0, sizeof(dpu));
    memset(dpb, 0, sizeof(dpb));
    memset(dpl, 0, sizeof(dpl));
    memset(dpr, 0, sizeof(dpr));

    FOR(i,1,n)
    REP(j,n){
        if(grid[i][j]=='#'){
        dpu[i][j] = dpu[i-1][j] + (grid[i-1][j]=='#');
        }
    }
    REP(j,n)
    FOR(i,1,n){
        if(grid[j][i]=='#'){
            dpl[j][i] = dpl[j][i-1] + (grid[j][i-1]=='#');
        }
    }

    for(int i = n-2;i>=0;--i)
    REP(j,n){
        if(grid[i][j]=='#'){
        dpb[i][j] = dpb[i+1][j] + (grid[i+1][j]=='#');
        }
    }
    REP(j,n)
    for(int i = n-2;i>=0;--i){
        if(grid[j][i]=='#'){
        dpr[j][i] = dpr[j][i+1] + (grid[j][i+1]=='#');
        }
    }

    int best = 0;

    REP(i,n)
    REP(j,n)
        if(grid[i][j]=='#') {
            best = max(best, min(dpr[i][j],min(dpl[i][j],min(dpu[i][j],dpb[i][j])))+1);
            // cout<<i<<' '<<j<<' '<<best<<endl;
        }

    cout<<best<<endl;
}

int main() {
    cin>>t;
    while(t--)process();

    return 0;
}