#include <bits/stdc++.h>
using namespace std;
#define MASK(x) (1LL << (x))
#define BIT(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end()
#define REP(i, n) for (int i = 0, _n = n; i < _n; ++i)
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define FORE(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define debug(...) "[" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
template <class A, class B> bool minimize(A &a, B b) { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b) { if (a < b) { a = b; return true; } return false; }
const int MAXN = 1e5 + 5;
struct Data {
int T, L, R, C;
} a[MAXN];
int N, M, dd[MAXN];
vector <int> cp;
long long dp[MAXN];
priority_queue <pair <long long, int>, vector <pair <long long, int>>, greater <pair <long long, int>>> pq, q[MAXN];
vector <int> ver;
void update(int u, int val, int id) {
for (int v = u; v <= (int) cp.size(); v += v & -v) {
q[v].emplace(val, id);
}
}
void get(int u, int t) {
for (; u > 0; u -= u & -u) {
while(!q[u].empty() && q[u].top().first <= t) {
ver.emplace_back(q[u].top().second); q[u].pop();
}
}
}
void you_make_it(void) {
cin >> N >> M;
FOR(i, 1, M) {
cin >> a[i].T >> a[i].L >> a[i].R >> a[i].C;
cp.emplace_back(a[i].L - a[i].T);
}
sort(cp.begin(), cp.end()); cp.erase(unique(cp.begin(), cp.end()), cp.end());
memset(dp, 0x3f, sizeof dp);
FOR(i, 1, M) {
update(lower_bound(cp.begin(), cp.end(), a[i].L - a[i].T) - cp.begin() + 1, a[i].L + a[i].T, i);
}
FOR(i, 1, M) {
if(a[i].L == 1) {
dp[i] = a[i].C;
dd[i] = 1;
pq.emplace(dp[i], i);
}
}
long long ans = 1E18;
while(!pq.empty()) {
auto [du, u] = pq.top(); pq.pop();
if(du != dp[u]) continue;
if(a[u].R == N) {
minimize(ans, du);
continue;
}
ver.clear();
get(upper_bound(cp.begin(), cp.end(), a[u].R - a[u].T + 1) - cp.begin(), a[u].R + a[u].T + 1);
for (auto i : ver) {
if(!dd[i] && minimize(dp[i], dp[u] + a[i].C)) {
pq.emplace(dp[i], i);
dd[i] = 1;
}
}
}
// FOR(i, 1, M) cout << dp[i] << " \n"[i == M];
cout << (ans >= 1E18 ? -1 : ans);
}
signed main() {
#ifdef LOCAL
freopen("TASK.inp", "r", stdin);
freopen("TASK.out", "w", stdout);
#endif
file("treatment");
auto start_time = chrono::steady_clock::now();
cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
you_make_it();
auto end_time = chrono::steady_clock::now();
cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;
return (0 ^ 0);
}
// Dream it. Wish it. Do it.
