/*
IN THE NAME OF GOD
*/
#include <bits/stdc++.h>
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef long double ld;
#define F first
#define S second
#define Mp make_pair
#define pb push_back
#define pf push_front
#define size(x) ((ll)x.size())
#define all(x) (x).begin(),(x).end()
#define kill(x) cout << x << '\n', exit(0);
#define fuck(x) cout << "(" << #x << " , " << x << ")" << endl
#define endl '\n'
const int M = 1e5+5, N = 3e5+23, lg = 17;
ll Mod = 1e9+7; //998244353;
inline ll MOD(ll a, ll mod=Mod) {a%=mod; (a<0)&&(a+=mod); return a;}
inline ll poww(ll a, ll b, ll mod=Mod) {
ll ans = 1;
a=MOD(a, mod);
while (b) {
if (b & 1) ans = MOD(ans*a, mod);
b >>= 1;
a = MOD(a*a, mod);
}
return ans;
}
int m, n, par[N], L[N], R[N], t[N], p[N], seg[N];
ll c[N], d[N * 3 * lg], id=1;
bool mark[N * 3 * lg];
vector<int> adj[N * 3 * lg];
vector<int> comp[2];
bool cmp(int i, int j) {
return (t[i] < t[j]);
}
void query(int v, int l, int r, int ind=1, int lc=1, int rc=(1<<lg)+1) {
if(lc >= r) return;
if(rc <= r) {
adj[v].pb(seg[ind]); return;
}
int mid = (lc+rc)/2;
query(v, l, r, 2*ind, lc, mid);
query(v, l, r, 2*ind+1, mid, rc);
}
void update(int ind, int v) {
adj[id].pb(seg[ind]);
adj[id].pb(v);
seg[ind] = id;
ind/=2; id++;
while(ind > 0) {
seg[ind] = id++;
adj[seg[ind]].pb(seg[2*ind]);
adj[seg[ind]].pb(seg[2*ind+1]);
ind /= 2;
}
}
int main () {
ios_base::sync_with_stdio(false), cin.tie(0);
cin>>n>>m; id = m + 1;
for(int i=1; i<=m; i++) {
cin>>t[i]>>L[i]>>R[i]>>c[i];
p[i] = i;
comp[0].pb(L[i]-t[i]);
comp[1].pb(L[i]+t[i]);
}
sort(p+1, p+m+1, cmp);
for(int i=(1<<(lg + 1)); i>=1; i--) {
seg[i] = id ++;
if(i < (1<<lg)) {
adj[seg[i]].pb(seg[2*i]);
adj[seg[i]].pb(seg[2*i+1]);
}
}
comp[0].pb(2e9); comp[1].pb(2e9);
sort(all(comp[0])); comp[0].resize(unique(all(comp[0]))-comp[0].begin());
sort(all(comp[1])); comp[1].resize(unique(all(comp[1]))-comp[1].begin());
for(int i=1; i<=m; i++) {
int ptr = lower_bound(all(comp[0]), R[p[i]]-t[p[i]]+2)-comp[0].begin();
if(ptr != 0) {
query(p[i], 1, ptr + 1);
}
ptr = lower_bound(all(comp[0]), L[p[i]]-t[p[i]])-comp[0].begin()+1;
update((1<<lg)+ptr-1, p[i]);
}
for(int i=(1<<(lg + 1)); i>=1; i--) {
seg[i] = id ++;
if(i < (1<<lg)) {
adj[seg[i]].pb(seg[2*i]);
adj[seg[i]].pb(seg[2*i+1]);
}
}
for(int i=m; i>=1; i--) {
int ptr = lower_bound(all(comp[1]), R[p[i]]+t[p[i]]+2)-comp[1].begin();
if(ptr != 0) {
query(p[i], 1, ptr + 1);
}
ptr = lower_bound(all(comp[1]), L[p[i]]+t[p[i]])-comp[1].begin()+1;
update((1<<lg)+ptr-1, p[i]);
}
priority_queue<pll, vector<pll>, greater<pll>> pq;
for(int i=1; i<=m; i++) {
if(L[i] == 1) {
pq.push({c[i], i});
}
}
while(size(pq) > 0) {
pll v = pq.top(); pq.pop();
if(mark[v.S] == 1) continue;
// fuck(v.S);
d[v.S] = v.F, mark[v.S] = 1;
for(auto u : adj[v.S]) {
if(mark[u] == 1) continue;
pq.push({v.F+(u <= m ? c[u] : 0ll), u});
}
}
ll ans = 2e18;
for(int i=1 ; i<=m; i++) {
if(d[i] == 0) continue;
if(R[i] == n) {
ans = min(ans, d[i]);
}
}
cout<<(ans==2e18 ? -1 : ans)<<endl;
return 0;
}
