#include <bits/stdc++.h>
using namespace std;

__attribute__((constructor))
void fast_io() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    int n, m;
    cin >> n >> m;
    vector a(n, vector<int>(n));
    for (auto& ai : a) for (auto& aij : ai) cin >> aij;

    int ans = INT_MAX;
    for (int flag = 0; flag < 1 << (n + 2); ++flag) {
        int x = __builtin_popcount(flag);
        if (x + n < m) continue;
        int cost = 0;
        vector used(n, vector<bool>(n));
        for (int j = 0; j < n; ++j) {
            if (flag >> j & 1) {
                for (int i = 0; i < n; ++i) {
                    cost += a[i][j];
                    used[i][j] = true;
                }
            }
        }
        if (flag >> n & 1) {
            for (int i = 0; i < n; ++i) {
                if (!used[i][i]) {
                    cost += a[i][i];
                    used[i][i] = true;
                }
            }
        }
        if (flag >> (n + 1) & 1) {
            for (int i = 0; i < n; ++i) {
                if (!used[i][n - 1 - i]) {
                    cost += a[i][n - 1 - i];
                    used[i][n - 1 - i] = true;
                }
            }
        }
        if (x == m) {
            ans = min(ans, cost);
            continue;
        }
        vector<int> row(n);
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < n; ++j) {
                if (!used[i][j]) row[i] += a[i][j];
            }
        }
        sort(row.begin(), row.end());
        for (int i = 0; i < m - x; ++i) cost += row[i];
        ans = min(ans, cost);
    }
    
    cout << ans << '\n';
}