/**************************************************************

    Problem: 2324

    User: gaotianyu1350

    Language: C++

    Result: Accepted

    Time:392 ms

    Memory:7620 kb

****************************************************************/

#include <cstdio>

#include <cstring>

#include <cmath>

#include <cstdlib>

#include <queue>

#include <iostream>

using namespace std;

#define MAXN 350

#define MAXM 300000

#define INF  0x3f3f3f3f

int point[MAXN], next[MAXM], v[MAXM], flow[MAXM], cap[MAXM], w[MAXM];

int lastedge[MAXN], dis[MAXN];

bool check[MAXN];

int tot = -1;

int n, m, people;

int map[MAXN][MAXN];

inline void init()

{

    memset(map, 0x7f, sizeof(map));

    memset(point, -1, sizeof(point));

    memset(next, -1, sizeof(next));

    tot = -1;

}

inline void addedge(int x, int y, int theCap, int theDis)

{

    tot++;

    next[tot] = point[x]; point[x] = tot;

    v[tot] = y; flow[tot] = 0; cap[tot] = theCap; w[tot] = theDis;

    tot++;

    next[tot] = point[y]; point[y] = tot;

    v[tot] = x; flow[tot] = 0; cap[tot] = 0; w[tot] = - theDis;

}

inline int addflow(int s, int t)

{

    int now = t;

    int ans = INF;

    while (now != s)

    {

        int temp = lastedge[now];

        ans = min(ans, cap[temp] - flow[temp]);

        now = v[lastedge[now] ^ 1];

    }

    now = t;

    while (now != s)

    {

        flow[lastedge[now]] += ans;

        flow[lastedge[now] ^ 1] -= ans;

        now = v[lastedge[now] ^ 1];

    }

    return ans;

}

bool spfa(int s, int t, int &maxflow, int &mincost)

{

    queue<int> q;

    while (!q.empty()) q.pop();

    memset(dis, 0x7f, sizeof(dis));

    memset(check, 0, sizeof(check));

    dis[s] = 0; check[s] = true; q.push(s);

    while (!q.empty())

    {

        int now = q.front(); q.pop();

        check[now] = false;

        for (int temp = point[now]; temp != -1; temp = next[temp])

            if (flow[temp] < cap[temp] && dis[now] + w[temp] < dis[v[temp]])

            {

                dis[v[temp]] = dis[now] + w[temp];

                lastedge[v[temp]] = temp;

                if (!check[v[temp]])

                    check[v[temp]] = true, q.push(v[temp]);

            }

    }

    if (dis[t] > INF) return false;

    int add = addflow(s, t);

    maxflow += add;

    mincost += add * dis[t];

    return true;

}

inline int solve(int s, int t)

{

    int maxflow = 0, mincost = 0;

    while (spfa(s, t, maxflow, mincost));

    /*{

        int tiaoshi = 1;

        tiaoshi++;

    }*/

    //printf("mflow :%d\n", maxflow);

    return mincost;

}

inline void build(int start, int end)

{

    addedge(start, 0, people, 0);

    for (int i = 1; i <= n; i++)

    {

        addedge(i, end, 1, 0);

        addedge(start, i + n, 1, 0);

        //addedge(i, i + n, INF, 0);

    }

    for (int k = 0; k <= n; k++)

    for (int i = 0; i <= n; i++)

    for (int j = 0; j <= n; j++)

        if (i != j)

        {

            if (map[i][k] < INF && map[k][j] < INF)

                map[i][j] = min(map[i][j], map[i][k] + map[k][j]);

            if (k == j && i < j && map[i][j] < INF)

                addedge(i == 0 ? 0 : i + n, j, INF, map[i][j]);

        }

}

int main()

{

    //freopen("input.txt", "r", stdin);

    init();

    scanf("%d%d%d", &n, &m, &people);

    for (int i = 1; i <= m; i++)

    {

        int x, y, z;

        scanf("%d%d%d", &x, &y, &z);

        if (z < map[x][y])

            map[x][y] = map[y][x] = z;

    }

    build(2 * n + 1, 2 * n + 2);

    printf("%d\n", solve(2 * n + 1, 2 * n + 2));

}