#include <iostream>
#include <map>
#include <algorithm>
#include <cmath>
#include <vector>

using namespace std;
int n;

void dfs(int v, vector<vector<int> > &g, int m, vector<bool> &used) {
    used[v] = true;
    for (int i = 0; i < n; ++i) {
        if (g[v][i] <= m && !used[i]) {
            dfs(i, g, m, used);
        }
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //cout.tie(0);

    cin >> n;
    vector<vector<int> > g(n, vector<int> (n));
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            cin >> g[i][j];
        }
    }
    int l = -1, r = 1e9;
    while (l + 1 != r) {
        int m = (l + r) / 2;
        vector<bool> used(n);
        dfs(0, g, m, used);
        bool f = true;
        for (int i = 0; i < n; ++i) {
            if (!used[i]) f = false;
        }
        if (f) {
            r = m;
        } else {
            l = m;
        }
    }
    cout << r;
    return 0;
}


/*
 4
 0 10 12 16
 11 0 8 9
 10 13 0 22
 13 10 17 0
 */