#include <bits/stdc++.h>
using namespace std;
#define sz(v) int(v.size())
#define ar array
typedef long long ll;
const int N = 2e5+10, MOD = 998244353;
const ll INF = 1e18+10;
template <class T>
using min_pq = priority_queue<T, vector<T>, greater<T>>;
void solve() {
int n, m; cin >> n >> m;
vector<ar<int, 4>> a(m);
for (auto& [t, l, r, x] : a) cin >> t >> l >> r >> x, --l, --r;
min_pq<pair<ll, int>> q;
vector<ll> dist(m, INF);
for (int i = 0; i < m; i++) {
auto [t, l, r, x] = a[i];
if (l == 0) {
dist[i] = x;
q.push({dist[i], i});
}
}
while (!q.empty()) {
auto [d_c, c] = q.top(); q.pop();
if (dist[c] != d_c) continue;
for (int i = 0; i < m; i++) {
auto [t, l, r, x] = a[i];
int shrink = abs(t - a[c][0]);
if (l - a[c][2] + shrink > 1) continue;
if (dist[c] + x < dist[i]) {
dist[i] = dist[c] + x;
q.push({dist[i], i});
}
}
}
ll ans = INF;
for (int i = 0; i < m; i++) {
auto [t, l, r, x] = a[i];
if (r == n-1) {
ans = min(ans, dist[i]);
}
}
if (ans >= INF) {
cout << -1 << '\n';
return;
}
cout << ans << '\n';
}
int main() {
ios::sync_with_stdio(false); cin.tie(0);
int T = 1;
// cin >> T;
while (T--) solve();
}
