#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> ovo(int n) {
    vector<vector<int>> matrix(n, vector<int>(n));
    int num = 1;
    int left = 0, right = n - 1, top = 0, bottom = n - 1;

    while (left <= right && top <= bottom) {
        for (int i = left; i <= right; ++i) {
            matrix[top][i] = num++;
        }
        top++;
        for (int i = top; i <= bottom; ++i) {
            matrix[i][right] = num++;
        }
        right--;
        if (top <= bottom) {
            for (int i = right; i >= left; --i) {
                matrix[bottom][i] = num++;
            }
            bottom--;
        }
        if (left <= right) {
            for (int i = bottom; i >= top; --i) {
                matrix[i][left] = num++;
            }
            left++;
        }
    }

    return matrix;
}
int main() {
    int n;
    cin >> n;
    vector<vector<int>> matrix = ovo(n);
    for (const auto& row : matrix) {
        for (int num : row) {
            cout << num << " ";
        }
        cout << endl;
    }
    return 0;
}

不用 vector 的只能度过一个相对失败的人生（