#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define eb emplace_back
#define pu push
#define ins insert
#define fi first
#define se second
#define all(a) a.begin(),a.end()
#define bruh ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define fu(x,a,b) for (auto x=a;x<=b;x++)
#define fd(x,a,b) for (auto x=a;x>=b;x--)
#define int ll
using namespace std;
//mt19937 mt(chrono::steady_clock::now().time_since_epoch().count());
/*
Competitive Programming notes that I need to study & fix my dumbass self:
1. Coding:
- Always be sure to check the memory of arrays (maybe use vectors), for loops
- Always try to maximize the memory if possible, even if you are going for subtasks
- Do not exploit #define int long long, it will kill you
2. Stress:
- Always try generating big testcases and try if they run
3. Time management:
- Don't overcommit or undercommit, always spend a certain amount of time to think a problem, don't just look at it and say I'm fucked
- Do not spend too much time coding brute-force solutions, they should be easily-codable solutions that don't take up too much time
Time management schedule:
Offline / LAH days (4 problems - 3h):
15' thinking of solution / idea
1. no idea: skip
2. yes idea: continue thinking for <= 15'
+ implementing: <= 20'
+ brute-force: <= 5'
+ test generator: <= 5'
I hate offline because I am dumb
*/
typedef pair<int, int> ii;
const int N = 2e5+5;
const int B = 750;
const int mod = 1e9+7;
const int inf = 1e18;
using cd = complex<double>;
const long double PI = acos(-1);
int power(int a,int b) {ll x = 1;if (a >= mod) a%=mod; while (b) {if (b & 1) x = x*a % mod;a = a*a % mod;b>>=1;}return x;}
struct node {
int t, l, r, c;
node(int t, int l, int r, int c): t(t), l(l), r(r), c(c) {}
bool operator<(const node &other) const {
return t < other.t;
}
};
int n,m;
vector<node> a;
priority_queue<ii, vector<ii>, greater<ii>> q;
bool vis[N];
struct segtree {
int st[4*N];
void update(int id, int l, int r, int i, int val)
{
if (l > i || r < i) return;
if (l == r)
{
st[id] = val;
return;
}
int mid = l+r>>1;
update(id*2, l, mid, i, val); update(id*2+1, mid+1, r, i, val);
st[id] = min(st[id*2], st[id*2+1]);
}
void get(int id, int l, int r, int u, int v, int val, int c)
{
if (l > v || r < u || v < u || st[id] > val) return;
if (l == r)
{
if (!vis[l]) q.push({c + a[l].c, l});
vis[l] = 1;
st[id] = inf;
return;
}
int mid = l+r>>1;
get(id*2, l, mid, u, v, val, c); get(id*2+1, mid+1, r, u, v, val, c);
st[id] = min(st[id*2], st[id*2+1]);
}
} st1, st2;
void solve()
{
cin>>n>>m;
for (int i = 1; i <= m; i++)
{
int t,l,r,c;
cin>>t>>l>>r>>c;
a.pb(node(t,l,r,c));
}
sort(all(a));
for (int i = 0; i < m; i++)
{
st1.update(1, 0, m-1, i, a[i].l-a[i].t), st2.update(1, 0, m-1, i, a[i].l+a[i].t);
}
for (int i = 0; i < m; i++) if (a[i].l == 1) q.push({a[i].c, i}), vis[i] = 1;
int ans = inf;
while (!q.empty())
{
int c = q.top().fi, i = q.top().se;
q.pop();
if (a[i].r == n) ans = min(ans, c);
st1.get(1, 0, m-1, 0, i-1, a[i].r-a[i].t+1, c);
st2.get(1, 0, m-1, i+1, m-1, a[i].r+a[i].t+1, c);
}
if (ans == inf) cout<<-1;
else cout<<ans;
}
/*
Go through the mistakes you usually make and revise your code, for god's sake...
*/
signed main()
{
bruh
//freopen("input.inp","r",stdin);
//freopen("output.inp","w",stdout);
int t = 1;
// cin>>t;
while (t--)
{
solve();
cout<<"\n";
}
}
