#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
typedef long long ll;
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
ll n, m;
cin >> n >> m;
vector<ll> T(m), L(m), R(m), C(m);
for(ll i=0; i<m; ++i) {
cin >> T[i] >> L[i] >> R[i] >> C[i];
}
vector<ll> targets;
ll inf = 1e18;
vector<ll> dist(m, inf);
auto check = [&](ll i, ll j) {
if(T[i] >= T[j]) return (L[j] - T[j] <= R[i] - T[i]);
return (L[j] + T[j] <= R[i] + T[i]);
};
for(ll i=0; i<m; ++i) {
if(L[i]==1) dist[i] = C[i];
if(R[i]==n) targets.push_back(i);
}
priority_queue<pair<ll, ll>> pq;
for(ll i=0; i<m; ++i) if(dist[i] < inf) pq.push({-dist[i], i});
while(pq.size()) {
auto[dv, v] = pq.top();
pq.pop(); dv*=-1;
if(dv!=dist[v]) continue;
for(ll u=0; u<m; ++u) {
if(!check(v,u)) continue;
if(dist[u] > dist[v] + C[u]) {
dist[u] = dist[v] + C[u];
pq.push({-dist[u], u});
}
}
}
ll ans = inf;
for(ll x : targets) {
ans = min(ans, dist[x]);
}
if(ans==inf) cout << "-1\n";
else cout << ans << "\n";
return 0;
}
