#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,int>;
const ll INF=LLONG_MAX/2;
struct Info{
int x,y,id;
bool real;
bool operator<(const Info &o)const{
return x<o.x||(x==o.x&&y<o.y);
}
};
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
int n,m;
cin >> m >> n;
vector<int> t(n),l(n),r(n),c(n);
for(int i=0;i<n;i++){
cin >> t[i] >> l[i] >> r[i] >> c[i];
}
vector<vector<int>> adj(n);
auto new_node=[&](){
adj.emplace_back(vector<int>());
return (int)adj.size()-1;
};
auto link=[&](int u,int v){
if(u!=-1&&v!=-1)adj[u].emplace_back(v);
};
vector<Info> a(2*n),b(2*n);
vector<int> in(2*n),out(2*n);
auto rec=[&](auto &&self,int l,int r){
if(l==r)return;
int m=(l+r)/2;
self(self,l,m);
self(self,m+1,r);
in[l]=a[l].real?-1:a[l].id;
for(int i=l+1;i<=m;i++){
link(in[i]=new_node(),in[i-1]);
if(!a[i].real)link(in[i],a[i].id);
}
out[m+1]=a[m+1].real?a[m+1].id:-1;
for(int i=m+2;i<=r;i++){
link(out[i]=new_node(),out[i-1]);
if(a[i].real)link(a[i].id,out[i]);
}
for(int i=l,j=m+1,p=l;p<=r;p++){
if(j>r||(i<=m&&a[i].y<=a[j].y)){
b[p]=a[i];
i++;
}else{
b[p]=a[j];
if(i>l)link(out[j],in[i-1]);
j++;
}
}
for(int i=l;i<=r;i++)a[i]=b[i];
};
for(int i=0;i<n;i++){
a[i*2]={-t[i],r[i]+t[i],i,true};
a[i*2+1]={-t[i],l[i]+t[i]-1,i,false};
}
sort(a.begin(),a.end());
rec(rec,0,2*n-1);
for(int i=0;i<n;i++){
a[i*2]={t[i],r[i]-t[i],i,true};
a[i*2+1]={t[i],l[i]-t[i]-1,i,false};
}
sort(a.begin(),a.end());
rec(rec,0,2*n-1);
vector<ll> dist(adj.size(),INF);
priority_queue<P,vector<P>,greater<P>> pq;
for(int i=0;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+(v<n?c[v]:0);
if(nd<dist[v]){
dist[v]=nd;
pq.emplace(nd,v);
}
}
}
ll ans=INF;
for(int i=0;i<n;i++){
if(r[i]==m){
ans=min(ans,dist[i]);
}
}
cout << (ans<INF?ans:-1LL);
}
