1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
#pragma GCC optimize("O3")
#include "bits/stdc++.h"
using namespace std;
#define all(x) x.begin(),x.end()
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << p.first << " " << p.second; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#define ASSERT(...) 42
#endif
typedef long long ll;
typedef vector<short> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const short oo = 1e4;
typedef bitset<400> bs;
void solve() {
    int n; cin >> n;
    vector<string> g(n);
    for(auto& i : g) cin >> i;
    // do BFS!
    vvi ord;
    vvi ds;
    auto bfs = [&](int s) {
        vi q = {s};
        vi d(n,oo);
        d[s]=0;
        for(int i=0;i<q.size();++i) {
            int at = q[i];
            for(int to=0;to<n;++to) {
                if(g[at][to]=='1') {
                    if(d[to]==oo) {
                        d[to]=d[at]+1;
                        q.push_back(to);
                    }
                }
            }
        }
        ord.push_back(q);
        ds.push_back(d);
    };
    for(int i=0;i<n;++i) bfs(i);
    vector<bs> full(n);
    
    for(int i=0;i<n;++i) for(int j=0;j<n;++j) full[i][j]=1;
    auto good = full;

    int x=n;
    auto isgood = [&](int i, int j) {
        auto my = good;
        for(int r=0;r<2;++r) {
            bs match = full[0];
            // everything guchi!
            auto it = ord[j].end();
            for(int at : ord[i]) {
                while(it!=ord[j].begin()) {
                    int who = *prev(it);
                    if(ds[i][at] + ds[j][who]>x) {
                        match[who]=0;
                        --it;

                    } else break;
                }
                my[at]|=match;
            }
            swap(i,j);
        }
        return my==full;
    };
    for(int i=0;i<n;++i) for(int j=i+1;j<n;++j) {
        while(x>=0 and isgood(i,j)) {
            --x;
            for(int i=0;i<n;++i) for(int j=0;j<n;++j) if(ds[i][j]==x+1) {
                good[i][j]=0;
            }
        }

    }
    cout << x+1;
    cout << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t; cin >> t;
    for(int i=0;i<t;++i) {
        // if(i) 
        solve();
    }
}

/*
1
2
01
10
*/