#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define int long long
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define rnd(l, r) uniform_int_distribution<int>(l, r)(rng)
using namespace std;
void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
int pow(int a,int b,int m){int ans=1;while(b){if(b&1){ans=(ans*a)%m;}b>>=1;a=(a*a)%m;}return ans;}
int binpow(int a,int b){int ans=1;while(b){if(b&1){ans=(ans*a);}b>>=1;a=(a*a);}return ans;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 1e5 + 1, inf = 1e18;
unordered_map <int, unordered_map<int, int> > dp;
void setmin(int &a, int b){
a = min(a, b);
}
main(){
iostream::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n, m;
cin >> n >> m;
vector <array <int, 4> > vp;
set <pair <int,pair <int,int> > > st;
for(int i = 0; i < m; i++){
int t, l, r, c;
cin >> t >> l >> r >> c;
vp.pb({t, l, r, c});
if(l == 1){
if(!dp[r].count(t))
dp[r][t] = c;
else
setmin(dp[r][t], c);
//cout << dp[r][t] <<" "<< r <<" "<< t << endl;
st.insert({dp[r][t], {r, t}});
}
}
while(!st.empty()){
int cost = st.begin() ->ff;
int f = st.begin() -> ss.ff;
int s = st.begin() -> ss.ss;
st.erase(st.begin());
//cout << cost << endl;
if(cost != dp[f][s])continue;
bool flag = 0;
for(auto &[t, l, r, c] : vp){
if(t > s){
if(l + t <= f + s + 1){
if(!dp[r].count(t) || dp[r][t] > cost + c){
dp[r][t]= cost + c;
st.insert({dp[r][t], {r, t}});
flag = 1;
}
}
}else if(t <= s){
if(l - t <= f - s + 1){
if(!dp[r].count(t) || dp[r][t] > cost + c){
dp[r][t] = cost + c;
st.insert({dp[r][t], {r, t}});
flag = 1;
}
}
}
}
//if(!flag)st.erase(st.begin());
}
int ans = inf;
for(auto x : dp[n]){
//cout <<"==="<< x.ff <<"-" << x.ss<< endl;
ans = min(ans, x.ss);
}
if(ans == inf)
cout <<"-1\n";
else
cout << ans << endl;
}
/*
* Before implementing the problem:
Do I understand the problem correctly?
Which places are tricky? What do I need to remember to implement them correctly?
Which place is the heaviest by implementation? Can I do it simpler?
Which place is the slowest? Where do I need to be careful about constant factors and where I can choose slower but simpler implementation?
----------------------------------
If not AC:
Did you remember to do everything to handle the tricky places you thought about before?
Is the solution correct?
Do I understand the problem correctly?
----------------------------------
If you have a test on which the solution gives wrong answer:
Is the solution doing what it was supposed to do?
Is the problem in the code or in the idea?
*/
