#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
#define int long long
#define fi first
#define se second
#define L(i, j, k) for (int i = (j); i <= (k); i++)
#define R(i, j, k) for (int i = (j); i >= (k); i--)
#define all(x) x.begin(), x.end()
const int N = 1e5 + 5;
const int inf = 1e18;
struct Treatment {
int t, l, r, c;
} arr[N];
int di[N];
vector<pair<int, int>> adj[2 * N];
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<>> pq;
void ae(int u, int v, int w) {
// cout << "addedge: " << u << " " << v << " " << w << '\n';
adj[u].push_back({v, w});
}
queue<int> q;
struct SegTree {
int size = 1;
vector<int> seg;
void init(int sz) {
int size = 1;
while (size < sz) size *= 2;
seg.assign(2 * size + 10, inf);
}
void update(int source, int k, int ql, int qr, int l, int r, int id) {
if (qr < l || r < ql) return;
if (ql <= l && r <= qr && seg[id] > k) return;
if (l == r) {
di[l] = min(di[l], di[source] + arr[l].c);
pq.push({di[l], l});
seg[id] = inf;
return;
}
int mid = (l + r) / 2;
update(source, k, ql, qr, l, mid, id * 2);
update(source, k, ql, qr, mid + 1, r, id * 2 + 1);
seg[id] = min(seg[id * 2], seg[id * 2 + 1]);
}
void force_update(int pos, int val, int l, int r, int id) {
if (l == r) {
seg[id] = val;
return;
}
int mid = (l + r) / 2;
if (pos <= mid) force_update(pos, val, l, mid, id * 2);
else force_update(pos, val, mid + 1, r, id * 2 + 1);
seg[id] = min(seg[id * 2], seg[id * 2 + 1]);
}
} ST1, ST2;
void solve() {
int n, m;
cin >> n >> m;
for (int i = 1; i <= m; i++) {
cin >> arr[i].t >> arr[i].l >> arr[i].r >> arr[i].c;
di[i] = inf;
}
sort(arr + 1, arr + m + 1, [] (auto x, auto y) { return x.t < y.t; });
ST1.init(m + 1); ST2.init(m + 1);
for (int i = 1; i <= m; i++) {
ST1.force_update(i, arr[i].l + arr[i].t, 1, m, 1);
ST2.force_update(i, arr[i].l - arr[i].t, 1, m, 1);
// cout << arr[i].t << " " << arr[i].l << " " << arr[i].r << " " << arr[i].c << '\n';
}
di[0] = 0;
for (int i = 1; i <= m; i++) {
if (arr[i].l == 1) {
di[i] = arr[i].c;
pq.push({di[i], i});
ST1.force_update(i, inf, 1, m, 1);
ST2.force_update(i, inf, 1, m, 1);
}
}
while (!pq.empty()) {
auto [dist, i] = pq.top();
pq.pop();
if (dist != di[i]) continue;
// cout << "pq " << dist << " " << i << '\n';
ST1.update(i, arr[i].r + 1 + arr[i].t, i + 1, m, 1, m, 1);
ST2.update(i, arr[i].r + 1 - arr[i].t, 1, i - 1, 1, m, 1);
}
int ans = inf;
for (int i = 1; i <= m; i++) if (arr[i].r == n) ans = min(ans, di[i]);
if (ans == inf) cout << "-1\n";
else cout << ans << '\n';
// sort projects, then point to interval edges
}
int32_t main() {
ios::sync_with_stdio(0); cin.tie(0);
int test = 1;
// cin >> test;
while (test--) solve();
}
