/*************************************
* author: marvinthang *
* created: 07.12.2023 11:09:20 *
*************************************/
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define left ___left
#define right ___right
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x) >> (i) & 1)
#define __builtin_popcount __builtin_popcountll
#define ALL(v) (v).begin(), (v).end()
#define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i)
#define REPD(i, n) for (int i = (n); i-- > 0; )
#define FOR(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define FORD(i, b, a) for (int i = (b), _a = (a); --i >= _a; )
#define FORE(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORDE(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define scan_op(...) istream & operator >> (istream &in, __VA_ARGS__ &u)
#define print_op(...) ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
#include "debug.h"
#else
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define DB(...) 23
#define db(...) 23
#define debug(...) 23
#endif
template <class U, class V> scan_op(pair <U, V>) { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
// end of template
const long long INF = 1e18;
struct Project {
int t, l, r, c;
};
void process(void) {
int n, m; cin >> n >> m;
vector <Project> prj(m);
for (auto &[t, u, v, c]: prj) cin >> t >> u >> v >> c;
priority_queue <pair <long long, int>, vector <pair <long long, int>>, greater <pair <long long, int>>> pq;
vector <long long> dist(m, -1);
REP(i, m) if (prj[i].l == 1) pq.emplace(dist[i] = prj[i].c, i);
vector <int> order(m);
iota(ALL(order), 0);
sort(ALL(order), [&] (int a, int b) { return prj[a].l - prj[a].t < prj[b].l - prj[b].t; });
vector <vector <pair <int, int>>> st(m * 4 + 23);
vector <int> v1(m), ptr(m * 4 + 23);
function<void(int, int, int)> build = [&] (int i, int l, int r) {
if (r - l == 1) {
v1[l] = prj[order[l]].l - prj[order[l]].t;
st[i].emplace_back(prj[order[l]].l + prj[order[l]].t, order[l]);
return;
}
int m = l + r >> 1;
build(i << 1, l, m);
build(i << 1 | 1, m, r);
merge(ALL(st[i << 1]), ALL(st[i << 1 | 1]), back_inserter(st[i]));
};
build(1, 0, m);
while (!pq.empty()) {
auto [du, u] = pq.top(); pq.pop();
if (du != dist[u]) continue;
if (prj[u].r == n) return void(cout << du << '\n');
int i = 1, l = 0, r = m;
int p1 = prj[u].r - prj[u].t + 1;
int p2 = prj[u].r + prj[u].t + 1;
while (true) {
if (r - l == 1) {
if (v1[l] <= p1 && !ptr[i] && st[i][0].fi <= p2) {
int v = st[i][ptr[i]].se;
if (dist[v] == -1) pq.emplace(dist[v] = du + prj[v].c, v);
++ptr[i];
}
break;
}
int m = l + r >> 1;
i <<= 1;
if (v1[m] <= p1) {
while (ptr[i] < (int) st[i].size() && st[i][ptr[i]].fi <= p2) {
int v = st[i][ptr[i]].se;
if (dist[v] == -1) pq.emplace(dist[v] = du + prj[v].c, v);
++ptr[i];
}
++i; l = m;
} else r = m;
}
}
cout << "-1\n";
}
int main(void) {
ios_base::sync_with_stdio(false); cin.tie(nullptr); // cout.tie(nullptr);
file("JOI20_treatment");
// int t; cin >> t; while (t--)
process();
// cerr << "Time elapsed: " << TIME << " s.\n";
return (0^0);
}
