#include <bits/stdc++.h>
#define se second
#define fs first
#define mp make_pair
#define pb push_back
#define ll long long
#define ii pair<ll,ll>
#define ld long double
#define SZ(v) (int)v.size()
#define ALL(v) v.begin(), v.end()
#define bit(msk, i) ((msk >> i) & 1)
#define iter(id, v) for(auto id : v)
#define rep(i,m,n) for(int i=(m); i<=(n); i++)
#define reb(i,m,n) for(int i=(m); i>=(n); i--)
using namespace std;
mt19937_64 rd(chrono :: steady_clock :: now().time_since_epoch().count());
ll Rand(ll l, ll r)
{
return uniform_int_distribution<ll> (l, r)(rd);
}
const int N = 2e5 + 7;
const int Mod =1e9 + 7;
const int szBL = 916;
const int INF = 2e9 + 7;
const int BASE = 137;
struct Data {
ll T, L, R, C;
};
int n, m;
Data a[N];
vector<pair<ll,ll>> ke[N];
ll Dist[N];
vector<ll> Val; int nVal;
struct Segment_Tree_Set {
int Range;
set<pair<int, int>> sval[N];
pair<int,int> st[N << 2];
void init (int n ) {
Range = n;
}
void Merge (int id) {
if (st[id << 1].fs <= st[id << 1 | 1].fs) st[id] = st[id << 1];
else st[id] = st[id << 1 | 1];
}
void update (int id, int l, int r, int pos, pair<int, int> cur) {
if (l > pos || r < pos) return;
if (l == r) {
sval[l].insert(cur);
st[id] = *sval[l].begin();
return;
}
int mid = l + r >> 1;
update (id << 1, l, mid, pos, cur);
update (id << 1 | 1, mid + 1, r, pos, cur);
Merge (id);
}
void deupdate (int id, int l, int r, int pos, pair<int,int> cur){
if (l > pos || r < pos) return;
if (l == r) {
sval[l].erase(sval[l].find(cur));
if (sval[l].empty()) st[id] = {INF, -1};
else st[id] = *sval[l].begin();
return;
}
int mid = l + r >> 1;
deupdate (id << 1, l, mid, pos, cur);
deupdate (id << 1 | 1, mid + 1, r, pos, cur);
Merge (id);
}
pair<int,int> get (int id, int l, int r, int u, int v) {
if (l > v || r < u) return {INF, -1};
if (l >= u && r <= v) return st[id];
int mid = l + r >> 1;
pair<int,int> p1 = get (id << 1, l, mid, u, v),
p2 = get (id << 1 | 1, mid + 1, r, u, v);
if (p1.fs <= p2.fs) return p1;
else return p2;
}
void update (int pos, pair<int,int> cur) {
update (1, 1, Range, pos, cur);
}
void deupdate (int pos, pair<int,int> cur) {
deupdate (1, 1, Range, pos, cur);
}
pair<int,int> get (int u, int v) {
return get (1, 1, Range, u, v);
}
}ST1, ST2;
void solution () {
cin >> n >> m;
rep (i, 1, m) {
cin >> a[i].T >> a[i].L >> a[i].R >> a[i].C;
--a[i].L;
}
rep (i, 1, m) {
Val.push_back(a[i].T);
}
sort (ALL(Val));
Val.resize(nVal = unique(ALL(Val)) - Val.begin());
ST1.init(nVal);
ST2.init(nVal);
/**
1: a[i].R + a[i].T >= a[j].R + a[j].T ti < tj
2: a[i].R - a[i].T >= a[j].L - a[j].T ti > tj
*/
auto CPR = [] (int val) {
return lower_bound(ALL(Val), val) - Val.begin() + 1;
};
rep (i, 1, m) {
int pos = CPR(a[i].T);
ST1.update (pos, mp(a[i].L + a[i].T, i));
ST2.update (pos, mp(a[i].L - a[i].T, i));
}
memset(Dist, 0x3f, sizeof Dist);
priority_queue<pair<ll,ll>, vector<pair<ll,ll>>, greater<pair<ll,ll>>> pq;
rep (i, 1, m) {
if (a[i].L == 0) {
pq.push({a[i].C, i});
Dist[i] = a[i].C;
}
}
while (!pq.empty()) {
int u = pq.top().se;
if (a[u].R == n) {
cout << Dist[u] <<"\n";
return;
}
pq.pop();
int pos = CPR(a[u].T);
while (1) {
int v = ST1.get(pos, nVal).se;
// cout << u <<" "<<v<<" a \n";
if (v == -1 || a[u].R + a[u].T < a[v].L + a[v].T) break;
Dist[v] = min(Dist[v], Dist[u] + a[v].C);
pq.push({Dist[v], v});
ST1.deupdate (CPR(a[v].T), mp(a[v].L + a[v].T, v));
}
while (1) {
int v = ST2.get(1, pos).se;
// cout << u <<" "<<v<<" b\n";
if (v == -1 || a[u].R - a[u].T < a[v].L - a[v].T) break;
Dist[v] = min(Dist[v], Dist[u] + a[v].C);
pq.push({Dist[v], v});
ST2.deupdate (CPR(a[v].T), mp(a[v].L - a[v].T, v));
}
}
cout << -1 <<"\n";
}
#define file(name) freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);
int main () {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
// file ("c");
int num_Test = 1;
// cin >> num_Test;
while (num_Test--)
solution();
}
/*
1 2
*/
