#include<iostream>
#include <bits/stdc++.h>

#define ld long double
#define ll long long
#define rep(i, a, b) for(int i = a ; i < b ; i ++)
#define sz(v) (int)v.size()
#define all(v) begin(v), end(v)
#define IO ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
struct Edge {
    int to;
    int cost;
    int cap, flow, backEdge;
};

struct MCMF {

    const int inf = 1000000010;
    int n;
    vector<vector<Edge>> g;

    MCMF(int _n) {
        n = _n + 1;
        g.resize(n);
    }

    void addEdge(int u, int v, int cap, int cost) {
        Edge e1 = {v, cost, cap, 0, (int) g[v].size()};
        Edge e2 = {u, -cost, 0, 0, (int) g[u].size()};
        g[u].push_back(e1);
        g[v].push_back(e2);
    }

    pair<int, int> minCostMaxFlow(int s, int t) {
        int flow = 0;
        int cost = 0;
        vector<int> state(n), from(n), from_edge(n);
        vector<int> d(n);
        deque<int> q;
        while (true) {
            for (int i = 0; i < n; i++)
                state[i] = 2, d[i] = inf, from[i] = -1;
            state[s] = 1;
            q.clear();
            q.push_back(s);
            d[s] = 0;
            while (!q.empty()) {
                int v = q.front();
                q.pop_front();
                state[v] = 0;
                for (int i = 0; i < (int) g[v].size(); i++) {
                    Edge e = g[v][i];
                    if (e.flow >= e.cap || (d[e.to] <= d[v] + e.cost))
                        continue;
                    int to = e.to;
                    d[to] = d[v] + e.cost;
                    from[to] = v;
                    from_edge[to] = i;
                    if (state[to] == 1) continue;
                    if (!state[to] || (!q.empty() && d[q.front()] > d[to]))
                        q.push_front(to);
                    else q.push_back(to);
                    state[to] = 1;
                }
            }
            if (d[t] == inf) break;
            int it = t, addflow = inf;
            while (it != s) {
                addflow = min(addflow,
                              g[from[it]][from_edge[it]].cap
                              - g[from[it]][from_edge[it]].flow);
                it = from[it];
            }
            it = t;
            while (it != s) {
                g[from[it]][from_edge[it]].flow += addflow;
                g[it][g[from[it]][from_edge[it]].backEdge].flow -= addflow;
                cost += g[from[it]][from_edge[it]].cost * addflow;
                it = from[it];
            }
            flow += addflow;
        }
        return {cost, flow};
    }
};

void doWork() {
    int n, k;
    cin >> n >> k;
    MCMF g(300);
    int s = 295, t = 294;
    g.addEdge(s, 1, k, 0);
    for (int i = 1; i <= n + 1; i++) {
        g.addEdge(i + (n + 1), t, 1, 0);
    }
    for (int i = 2; i <= n + 1; i++) {
        g.addEdge(s, i, 1, 0);
    }

    for (int i = 1; i <= n; i++) {
        for (int j = i + 1; j <= n + 1; j++) {
            int c;
            cin >> c;
            g.addEdge(i, j + (n + 1), 1, c);
        }
    }
    pair<int, int> ans = g.minCostMaxFlow(s, t);
    cout << ans.first;
}

int main() {
    IO

    int t = 1;
//    cin >> t;
    for (int i = 1; i <= t; i++) {
        //  cout << "Case #" << i << ": ";
        doWork();
    }
}