// author : thembululquaUwU
// 3.9.2024
#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define endl '\n'
using namespace std;
using ll = long long;
using ii = pair <int, int>;
using li = pair <ll, int>;
using vi = vector <int>;
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
const ll inf = 1e18;
void maxl(auto &a, auto b) {a = max(a, b);}
void minl(auto &a, auto b) {a = min(a, b);}
struct project{
int t, l, r, c;
bool operator < (project other){
return l - t < other.l - other.t;
}
} p[N];
int NN, m;
ll d[N], Min[4 * N];
void build(int s = 1, int l = 1, int r = m){
if (l == r){
Min[s] = p[l].l + p[l].t;
return;
}
int mid = l + r >> 1;
build(s << 1, l, mid); build(s << 1 | 1, mid + 1, r);
Min[s] = min(Min[s << 1], Min[s << 1 | 1]);
}
priority_queue <li, vector <li>, greater <li>> qu;
void get(int u, int v, ll k, int s = 1, int l = 1, int r = m){
if (p[l].l - p[l].t > u || Min[s] > v) return;
if (l == r){
if (d[l] == inf){
d[l] = k + p[l].c;
qu.push({d[l], l});
}
Min[s] = inf;
return;
}
int mid = l + r >> 1;
get(u, v, k, s << 1, l, mid); get(u, v, k, s << 1 | 1, mid + 1, r);
Min[s] = min(Min[s << 1], Min[s << 1 | 1]);
}
void solve(){
cin >> NN >> m;
for (int i = 1; i <= m; ++ i){
cin >> p[i].t >> p[i].l >> p[i].r >> p[i].c;
d[i] = inf;
}
sort(p + 1, p + m + 1); build();
for (int i = 1; i <= m; ++ i) if (p[i].l == 1){
d[i] = p[i].c;
qu.push({d[i], i});
}
while (qu.size()){
auto [du, u] = qu.top(); qu.pop();
get(p[u].r - p[u].t + 1, p[u].r + p[u].t + 1, du);
}
ll ans = inf;
for (int i = 1; i <= m; ++ i) if (p[i].r == NN) minl(ans, d[i]);
if (ans == inf) cout << -1;
else cout << ans;
}
int main(){
if (fopen("pqh.inp", "r")){
freopen("pqh.inp", "r", stdin);
freopen("pqh.out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int t = 1; // cin >> t;
while (t --) solve();
return 0;
}
