#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T gcd(T a, T b) {
  return (b) == 0 ? (a) : gcd((b), ((a) % (b)));
}
template <class T>
inline T lcm(T a, T b) {
  return ((a) / gcd((a), (b)) * (b));
}
template <class T>
inline T BigMod(T Base, T power, T M = 1000000007) {
  if (power == 0) return 1;
  if (power & 1)
    return ((Base % M) * (BigMod(Base, power - 1, M) % M)) % M;
  else {
    T y = BigMod(Base, power / 2, M) % M;
    return (y * y) % M;
  }
}
template <class T>
inline T ModInv(T A, T M = 1000000007) {
  return BigMod(A, M - 2, M);
}
int fx[] = {-1, +0, +1, +0, +1, +1, -1, -1, +0};
int fy[] = {+0, -1, +0, +1, +1, -1, +1, -1, +0};
int day[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int n, m, k, s[100005], t[100005], d[100005];
long long w[100005], dp[100005][201], tree[4 * 100005], pk[4 * 100005];
vector<pair<pair<long long, long long>, pair<int, int> > > v;
pair<long long, long long> ans[100005];
bool cmp(const pair<pair<long long, long long>, pair<int, int> > &a,
         const pair<pair<long long, long long>, pair<int, int> > &b) {
  if (a.first.first == b.first.first) return a.first.second > b.first.second;
  return a.first.first > b.first.first;
}
void update(int node, int b, int e, int l, int r, long long ww, int dd) {
  if (b > r || l > e) return;
  if (tree[node] == 1e17) {
    if (b == e) {
      tree[node] = ww;
      ans[b] = pair<long long, long long>(ww, dd);
      return;
    }
    int mid = (b + e) >> 1;
    int left = 2 * node;
    int right = left + 1;
    update(left, b, mid, l, r, ww, dd);
    update(right, mid + 1, e, l, r, ww, dd);
    tree[node] = max(tree[left], tree[right]);
  }
}
long long giveres(int pos, int dis) {
  if (pos == n + 1) return 0;
  long long &ret = dp[pos][dis];
  if (ret != -1) return ret;
  ret = 1e17;
  if (dis < m) {
    ret = min(ret, giveres(pos + 1, dis + 1));
  }
  if (ans[pos].first > 0)
    ret = min(ret, giveres(ans[pos].second + 1, dis) + ans[pos].first);
  else
    ret = min(ret, giveres(pos + 1, dis));
  return ret;
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m >> k;
  for (int i = 0; i < k; i++) {
    cin >> s[i] >> t[i] >> d[i] >> w[i];
    v.push_back(pair<pair<long long, long long>, pair<int, int> >(
        pair<long long, long long>(w[i], d[i]), pair<int, int>(s[i], t[i])));
  }
  sort(v.begin(), v.end(), cmp);
  for (int i = 0; i < 4 * 100005; i++) tree[i] = 1e17;
  for (int i = 0; i < k; i++) {
    pair<pair<long long, long long>, pair<int, int> > x = v[i];
    update(1, 1, n, x.second.first, x.second.second, x.first.first,
           x.first.second);
  }
  memset(dp, -1, sizeof(dp));
  cout << giveres(1, 0);
  return 0;
}
