#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
const int N = 501000, M = 4000100;
int head[N], cur[N], to[M], nxt[M], n, m, s, t, tot = 2, u, v, pre[M];
i64 cap[M], cost[M], a, b, dis[M], h[M];
bool vis[N];
inline void add(int u, int v, i64 a, i64 b) {
    to[tot] = v, nxt[tot] = head[u], cap[tot] = a, cost[tot] = b, head[u] = tot++;
    to[tot] = u, nxt[tot] = head[v], cap[tot] = 0, cost[tot] = -b, head[v] = tot++;
}
int g = 0;
inline bool dijkstra() {
    // cerr << "dijkstra!\n";
    g++;
    using dit = pair<i64, int>;
    for (int i = 0; i <= t; i++) h[i] += dis[i];
    priority_queue<dit, vector<dit>, greater<>> q;
    int v = 0;
    memset(dis, 0x3f, sizeof(dis)), dis[s] = 0, q.push(make_pair(0, s)), memcpy(cur, head, sizeof(cur));
    while (!q.empty()) {
        dit p = q.top();
        q.pop();
        if (p.first != dis[p.second]) continue;
        int o = p.second;
        v++;
        for (int i = head[o]; i; i = nxt[i])
            if (cap[i] && dis[to[i]] > dis[o] + cost[i] + h[o] - h[to[i]]) {
                assert(cost[i] + h[o] - h[to[i]] >= 0); // printf("%d -> %d : %lld\n", o, to[i], cost[i] + h[o] - h[to[i]]), exit(0);
                dis[to[i]] = dis[o] + cost[i] + h[o] - h[to[i]], q.push({dis[to[i]], to[i]}), pre[to[i]] = i ^ 1;
            }
    }
    // cerr << "!! " << v << endl;
    // printf("dijkstra debug :\n");
    // for (int i = s; i <= t; i++) printf("%d : %lld %lld\n", i, dis[i], dis[i] + h[i]);
    return dis[t] != dis[t + 1];
}
i64 mincost, maxflow;
bool dfs(int n) {
    // printf("dfs %d\n", n);
    vis[n] = 1;
    if (n == t) return vis[n] = 0, true;
    for (int &i = cur[n]; i; i = nxt[i])
        if (!vis[to[i]] && dis[to[i]] + h[to[i]] == dis[n] + h[n] + cost[i] && cap[i]) {
            bool t = dfs(to[i]);
            if (!t) continue;
            return cap[i] -= 1, cap[i ^ 1] += 1, mincost += cost[i], vis[n] = 0, true;
        }
    return vis[n] = 0, false;
}
void dinic() {
    while (dijkstra()) {
        for (int p = t; p; p = to[pre[p]]) {
            cap[pre[p]]++, cap[pre[p] ^ 1]--, mincost += cost[pre[p] ^ 1];
        }
        // bool b = dfs(s); // printf("%d\n", flow);}  
        // if (!b) printf("fatal error!\n"), exit(0);
    }
}
int k;
int main() {
    // freopen("1.in", "r", stdin);
    scanf("%d%d%d", &n, &m, &k);
    s = 0, t = n + 1;
    add(s, 1, 100, 0), add(n, t, k, 0);
    for (int i = 2; i <= n; i++) add(i - 1, i, 100, 0);
    for (int i = 1; i <= m; i++) {
        int l, r, a;
        scanf("%d%d%d", &l, &r, &a);
        add(l - 1, r, 1, -a);
    }
    memset(h, 0x3f, sizeof(h)), h[s] = 0;
    for (int i = s; i <= t; i++)
        for (int j = head[i]; j; j = nxt[j])
            if (cap[j]) h[to[j]] = min(h[to[j]], h[i] + cost[j]);
    // if (n >= 2491) return !printf("done!\n");
    // while (true) {
    //     bool flag = false;
    //     for (int i = 0; i <= n + 1; i++)
    //         for (int j = head[i]; j; j = nxt[j])
    //             if (cap[j] && h[to[j]] > h[i] + cost[j]) flag = true, h[to[j]] = h[i] + cost[j];
    //     if (!flag) break;
    // }
    // printf("done!\n");
    // for (int i = 0; i <= n + 1; i++) printf("%d : %d\n", i, h[i]);
    // for (int i = 1; i <= 6; i++) dijkstra();
    dinic();
    printf("%lld\n", -mincost);
    // cerr << g << endl;
    return 0;
}