#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int nx=1e5+5;
ll n, m, vs[nx], res=1e18;
priority_queue<pair<ll, ll>, vector<pair<ll, ll>>, greater<pair<ll, ll>>> pq;
struct info
{
ll t, l, r, c;
info(ll t=0, ll l=0, ll r=0, ll c=0): t(t), l(l), r(r), c(c){}
bool operator<(const info &o) const {return t<o.t;}
} d[nx];
struct segtree
{
ll mn[4*nx];
void update(int l, int r, int i, int idx, ll vl)
{
if (idx<l||r<idx) return;
if (l==r) return mn[i]=vl, void();
int md=(l+r)/2;
update(l, md ,2*i, idx, vl);
update(md+1, r, 2*i+1, idx, vl);
mn[i]=min(mn[2*i], mn[2*i+1]);
}
void query(int l, int r, int i, int ql, int qr, ll vl, ll cw)
{
if (qr<l||r<ql||qr<ql||mn[i]>vl) return;
if (l==r)
{
if (!vs[l]) pq.push({cw+d[l].c, l});
vs[l]=1;
mn[i]=1e18;
return;
}
int md=(l+r)/2;
query(l, md, 2*i, ql, qr, vl ,cw);
query(md+1, r, 2*i+1, ql, qr, vl, cw);
mn[i]=min(mn[2*i], mn[2*i+1]);
}
} ls, mr;
int main()
{
cin.tie(NULL)->sync_with_stdio(false);
cin>>n>>m;
for (int i=1; i<=m; i++) cin>>d[i].t>>d[i].l>>d[i].r>>d[i].c;
sort(d+1, d+m+1);
for (int i=1; i<=m; i++) ls.update(1, m, 1, i, d[i].l-d[i].t), mr.update(1, m, 1, i, d[i].l+d[i].t);
for (int i=1; i<=m; i++) if (d[i].l==1) pq.push({d[i].c, i}), vs[i]=1;
while (!pq.empty())
{
auto [cw, i]=pq.top();
pq.pop();
//cout<<"debug "<<i<<' '<<d[i].l<<' '<<d[i].r<<' '<<cw<<'\n';
if (d[i].r==n) res=min(res, cw);
ls.query(1, m ,1, 1, i-1, d[i].r-d[i].t+1, cw);
mr.query(1, m, 1, i+1, m, d[i].r+d[i].t+1, cw);
}
if (res==1e18) cout<<-1;
else cout<<res;
}
