#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define x first
#define y second
ll N, M, T[100005], L[100005], R[100005], C[100005], D[100005];
vector<ll> G[100005];
set<pair<ll, ll>> Coord[100005];
struct SegTree{
set<pair<ll, ll>> T[400005];
void init(ll n, ll s, ll e){
if(s == e){
T[n] = Coord[s]; return;
}
ll m = (s + e) / 2;
init(n * 2, s, m); init(n * 2 + 1, m + 1, e);
T[n] = T[n * 2];
for(auto f : T[n * 2 + 1]) T[n].insert(f);
}
void qry(ll n, ll s, ll e, ll r, ll t, vector<ll> &V){
if(s > r) return;
if(e <= r){
for(auto it = T[n].begin(); it != T[n].end(); ){
if(it->x <= t){
V.push_back(it->y);
it = T[n].erase(it);
} else {
break;
}
}
return;
}
ll m = (s + e) / 2;
qry(n * 2, s, m, r, t, V); qry(n * 2 + 1, m + 1, e, r, t, V);
}
}seg;
int main(){
cin.tie(0) -> sync_with_stdio(0);
cin >> N >> M;
fill(D, D + 100005, 1e18);
priority_queue<pair<ll, ll>> PQ;
vector<ll> cp;
for(ll i = 1; i <= M; i++){
cin >> T[i] >> L[i] >> R[i] >> C[i];
R[i]++;
if(L[i] == 1){
D[i] = C[i]; PQ.push({-C[i], i});
}
cp.push_back(L[i] - T[i]);
}
sort(cp.begin(), cp.end());
cp.erase(unique(cp.begin(), cp.end()), cp.end());
for(ll i = 1; i <= M; i++){
if(L[i] == 1) continue;
Coord[lower_bound(cp.begin(), cp.end(), L[i] - T[i]) - cp.begin() + 1].insert({L[i] + T[i], i});
}
seg.init(1, 1, 100000);
ll Ans = 1e18;
while(!PQ.empty()){
ll c = -PQ.top().x, u = PQ.top().y; PQ.pop();
if(R[u] == N + 1){
Ans = min(Ans, c);
}
vector<ll> V;
seg.qry(1, 1, 100000, upper_bound(cp.begin(), cp.end(), R[u] - T[u]) - cp.begin(), R[u] + T[u], V);
for(auto v : V){
if(D[v] <= D[u] + C[v]) continue;
D[v] = D[u] + C[v];
PQ.push({-D[v], v});
}
}
cout << (Ans == 1e18 ? -1 : Ans);
}
