#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) a.size()
#define fi first
#define se second
#define all(a) a.begin(),a.end()
typedef long long int ll;
typedef pair<ll,ll> pii;
const int MAXN = 2e5+1;
ll t[MAXN],l[MAXN],r[MAXN],c[MAXN],dist[MAXN];
int tc[MAXN];
bool ded[MAXN];
vector<pii>adj[MAXN];
vector<int>crd,add[MAXN];
set<pii>s0[4*MAXN],s1[4*MAXN];
void build(int v,int L,int R){
if(L==R){
for(int x:add[L]){
s0[v].insert({l[x] + t[x],x});
s1[v].insert({l[x] - t[x],x});
}
return;
}
int tm = (L+R)/2;
build(2*v,L,tm);
build(2*v+1,tm+1,R);
for(auto x:s0[2*v])s0[v].insert(x);
for(auto x:s0[2*v+1])s0[v].insert(x);
for(auto x:s1[2*v])s1[v].insert(x);
for(auto x:s1[2*v+1])s1[v].insert(x);
}
vector<int>upd;
void query0(int v,int l,int r,int tl,int tr,int val){ //when t[i] > t[j]
if(l>r)return;
if(l==tl && r==tr){
while(!s0[v].empty()){
auto it = s0[v].upper_bound(make_pair(val,2e9));
if(it==s0[v].begin())break;
it--;
if(ded[it->se]){
s0[v].erase(it);
continue;
}else{
ded[it->se] = 1;
upd.pb(it->se);
s0[v].erase(it);
}
}
return;
}
int tm = (tl+tr)/2;
query0(2*v,l,min(r,tm),tl,tm,val);
query0(2*v+1,max(l,tm+1),r,tm+1,tr,val);
}
void query1(int v,int l,int r,int tl,int tr,int val){ //when t[i] > t[j]
if(l>r)return;
if(l==tl && r==tr){
while(!s1[v].empty()){
auto it = s1[v].upper_bound(make_pair(val,2e9));
if(it==s1[v].begin())break;
it--;
if(ded[it->se]){
s1[v].erase(it);
continue;
}else{
ded[it->se] = 1;
upd.pb(it->se);
s1[v].erase(it);
}
}
return;
}
int tm = (tl+tr)/2;
query1(2*v,l,min(r,tm),tl,tm,val);
query1(2*v+1,max(l,tm+1),r,tm+1,tr,val);
}
//ri >= lj + abs(t[i]-t[j])
//if t[i] > t[j]
//ri - t[i] >= lj - t[j]
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
int main()
{
owo
int n,m;
cin>>n>>m;
for(int i=0;i<m;i++){
cin>>t[i]>>l[i]>>r[i]>>c[i];
crd.pb(t[i]);
l[i]--;
}
sort(all(crd));
crd.resize(unique(all(crd)) - crd.begin());
int ss = sz(crd);
for(int i=0;i<m;i++){
tc[i] = lower_bound(all(crd),t[i]) - crd.begin();
add[tc[i]].pb(i);
}
build(1,0,ss-1);
//for(int i=0;i<m;i++)cout<<tc[i]<<" ";
//cout<<'\n';
priority_queue<pii,vector<pii>,greater<pii>>pq;
for(int i=0;i<m;i++){
dist[i] = 1e18;
if(l[i] == 0){
ded[i] = 1;
dist[i] = c[i];
pq.push({c[i],i});
}
}
while(!pq.empty()){
pii v = pq.top();
//cout<<v.se<<'\n';
pq.pop();
upd.clear();
query0(1,tc[v.se],ss-1,0,ss-1,r[v.se] + t[v.se]);
query1(1,0,tc[v.se],0,ss-1,r[v.se] - t[v.se]);
for(int x:upd){
//cout<<v.se<<" "<<x<<'\n';
if(dist[x] > dist[v.se] + c[x]){
dist[x] = dist[v.se] + c[x];
pq.push({dist[x],x});
}
}
}
ll ans = 1e18;
for(int i=0;i<m;i++){
if(r[i] == n)ans = min(ans,dist[i]);
}
if(ans==1e18)ans=-1;
cout<<ans;
}
