#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using P =pair<ll,int>;
const int N=1e5+5;
const ll INF=LLONG_MAX/2;
int n,m;
int t[N],l[N],r[N],c[N];
vector<int> adj[N];
priority_queue<P,vector<P>,greater<P>> pq;
ll dist[N];
ll ans=INF;
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
cin >> m >> n;
for(int i=1;i<=n;i++){
cin >> t[i] >> l[i] >> r[i] >> c[i];
}
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++){
if(i==j)continue;
if(t[i]<=t[j]){
if(r[i]+t[i]>=l[j]+t[j]-1){
adj[i].emplace_back(j);
}
}else{
if(r[i]-t[i]>=l[j]-t[j]-1){
adj[i].emplace_back(j);
}
}
}
}
for(int i=1;i<=n;i++){
dist[i]=INF;
}
for(int i=1;i<=n;i++){
if(l[i]==1){
dist[i]=c[i];
pq.emplace(c[i],i);
}
}
while(!pq.empty()){
auto [d,u]=pq.top();
pq.pop();
if(d>dist[u])continue;
for(auto v:adj[u]){
ll nd=d+c[v];
if(nd<dist[v]){
dist[v]=nd;
pq.emplace(nd,v);
}
}
}
for(int i=1;i<=n;i++){
if(r[i]==m){
ans=min(ans,dist[i]);
}
}
cout << (ans<INF?ans:-1LL);
}
