#include <bits/stdc++.h>
//#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
using namespace std;
typedef pair < long long, long long > pll;
typedef unsigned long long ull;
typedef pair < int, int > pii;
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;
typedef long long ll;
typedef double db;
const int inf = 1e9, maxn = 4e5 + 148, mod = 1e9 + 7, N = 1e5 + 11;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 333;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = 3.14159265359;
const ll INF = 1e18;
ll d[N];
vi xx, toDel;
int n, m, x[N];
vpii T[N << 2][2];
set < pair < ll, int > > q;
struct project {
ll c;
int t, l, r;
} a[N];
void add (int pos, int lvl, pii x, int v = 1, int tl = 0, int tr = sz(xx) - 1) {
T[v][lvl].pb(x);
if (tl == tr)
return;
int tm = (tl + tr) >> 1;
if (pos <= tm)
add(pos, lvl, x, v << 1, tl, tm);
else
add(pos, lvl, x, v << 1 | 1, tm + 1, tr);
}
void f (int l, int r, int lvl, int X, ll Y, int v = 1, int tl = 0, int tr = sz(xx) - 1) {
if (l > r || l > tr || tl > r)
return;
if (l <= tl && tr <= r) {
while (sz(T[v][lvl]) && T[v][lvl].back().f <= X) {
int i = T[v][lvl].back().s;
if (d[i] == -1) {
d[i] = Y + a[i].c;
q.insert({d[i], i});
}
T[v][lvl].ppb();
}
return;
}
int tm = (tl + tr) >> 1;
f(l, r, lvl, X, Y, v << 1, tl, tm);
f(l, r, lvl, X, Y, v << 1 | 1, tm + 1, tr);
}
void Sort (int v = 1, int tl = 0, int tr = sz(xx) - 1) {
sort(all(T[v][0]));
sort(all(T[v][1]));
reverse(all(T[v][0]));
reverse(all(T[v][1]));
if (tl == tr)
return;
int tm = (tl + tr) >> 1;
Sort(v << 1, tl, tm);
Sort(v << 1 | 1, tm + 1, tr);
}
main () {
memset(d, -1, sizeof(d));
scanf("%d%d", &n, &m);
for (int i = 1; i <= m; ++i) {
scanf("%d%d%d%lld", &a[i].t, &a[i].l, &a[i].r, &a[i].c);
++a[i].r;
xx.pb(a[i].t);
}
sort(all(xx));
xx.resize(unique(all(xx)) - xx.begin());
for (int i = 1; i <= m; ++i) {
x[i] = lower_bound(all(xx), a[i].t) - xx.begin();
if (a[i].l == 1) {
d[i] = a[i].c;
q.insert({d[i], i});
} else {
add(x[i], 0, {a[i].l + a[i].t, i});
add(x[i], 1, {a[i].l - a[i].t, i});
}
}
Sort();
while (sz(q)) {
int v = q.begin()->s;
q.erase(q.begin());
f(x[v], m - 1, 0, a[v].r + a[v].t, d[v]);
f(0, x[v], 1, a[v].r - a[v].t, d[v]);
}
ll mn = INF;
for (int i = 1; i <= m; ++i)
if (a[i].r == n + 1 && d[i] > -1)
mn = min(mn, d[i]);
if (mn == INF)
mn = -1;
printf("%lld\n", mn);
}
