#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, int> pii;
#define fi first
#define se second
#define mp make_pair
#define fastIO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
const int N = (int)1e5 + 10;
const ll inf = (ll)1e18;
ll T[N];
ll L[N];
ll R[N];
ll C[N];
ll dist[N];
bool pro[N];
vector<int> lis;
struct segm{
set<pii> kick[N*4+512];
void ins(int node, int cl, int cr, int id, ll fa, int fb){
kick[node].insert(mp(fa,fb));
if(cl == cr) return;
int mid = (cl + cr) / 2;
if(mid >= id)
ins(node * 2, cl, mid, id, fa, fb);
else
ins(node * 2 + 1, mid + 1, cr, id, fa, fb);
}
void get(int node, int cl, int cr, int tl, int tr, ll val, int mode){
if(cr < tl || cl > tr) return;
if(cl >= tl && cr <= tr){
if(mode == 0){ // get <= val
auto it = kick[node].lower_bound(mp(val + 1, -1));
while(it != kick[node].begin()){
it -- ;
lis.push_back(it->se);
it = kick[node].erase(it);
}
}
else{
auto it = kick[node].lower_bound(mp(val, -1));
while(it != kick[node].end()){
lis.push_back(it->se);
it = kick[node].erase(it);
}
}
return;
}
int mid = (cl + cr) / 2;
get(node * 2, cl, mid, tl, tr, val, mode);
get(node * 2 + 1, mid + 1, cr, tl, tr, val, mode);
}
};
segm t1, t2;
int main(){
fastIO;
int n, m;
cin >> n >> m;
vector<pii> zz;
for(int i = 1; i <= m; i ++ ){
cin >> T[i] >> L[i] >> R[i] >> C[i];
zz.push_back(mp(T[i], i));
}
sort(zz.begin(), zz.end());
for(int i = 0 ; i < m ; i ++ ){
t1.ins(1, 0, m - 1, i, T[zz[i].se] + L[zz[i].se],zz[i].se);
t2.ins(1, 0, m - 1, i, L[zz[i].se] - 1 - T[zz[i].se],zz[i].se);
}
priority_queue<pii, vector<pii>, greater<pii>> pq;
for(int i = 1; i <= m ; i ++ ){
dist[i] = inf;
if(L[i] == 1){
dist[i] = C[i];
pq.push(mp(C[i], i));
}
}
int id;
ll outp = inf;
int idx;
while(!pq.empty()){
id = pq.top().se;
pq.pop();
if(R[id] == n){
outp = min(outp, dist[id]);
}
idx = lower_bound(zz.begin(), zz.end(), mp(T[id], -1)) - zz.begin();
lis.clear();
t1.get(1, 0, m - 1, idx, m - 1, R[id] + 1 + T[id],0);
t2.get(1, 0, m - 1, 0, idx - 1, R[id] - T[id], 0);
for(auto x : lis){
if(dist[x] == inf){
dist[x] = dist[id] + C[x];
pq.push(mp(dist[x], x));
}
}
}
if(outp == inf)
cout << "-1\n";
else
cout << outp << "\n";
return 0;
}
