#include <bits/stdc++.h>
using namespace std;
#define int long long
struct plan{
int t,l,r,c;
plan(int t,int l,int r,int c):t(t),l(l-1),r(r+1),c(c){}
bool operator<(const plan& other)const{
return c<other.c;
}
};
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n,m;
cin >> n >> m;
list<plan> plans;
priority_queue<pair<int,plan>> q;
for(int i=1;i<=m;i++){
int t,l,r,c;cin>>t>>l>>r>>c;
if(l==1) q.emplace(-c,plan(t,l,r,c));
else plans.emplace_back(t,l,r,c);
}
while(!q.empty()){
auto [dist,curr] = q.top();q.pop();
if(curr.r==n+1){
cout << -dist << '\n';
return 0;
}
auto iter = plans.begin();
while(iter!=plans.end()){
if(iter->t+iter->l<curr.r+curr.t and curr.t-curr.r<iter->t-iter->l){
q.emplace(dist-iter->c,*iter);
iter=plans.erase(iter);
} else iter++;
}
}
cout << "-1\n";
}
