#include<cstdio>
#include<algorithm>
#include<vector>
#include<set>
#define pii pair<int,int>
#define pil pair<int, long long>
#define pli pair<long long, int>
#define N_ 101000
#define SZ 131072
using namespace std;
struct AA {
int t, l, r, c;
}P[N_];
long long D[N_], INF = 1e18;
int L, n;
struct Tree {
int X[N_], Y[N_], Loc[N_][20];
int n, PV[SZ+SZ], ReNum[N_];
pli IT[SZ + SZ], MM[SZ+SZ];
vector<pii>TP;
vector<int>YY[SZ + SZ], Num[SZ+SZ], chk[SZ + SZ];
set<pil>Set[SZ + SZ];
struct point {
int y, num;
}w[N_];
void Add(AA t, int num) {
n++;
X[n] = t.l + t.t;
Y[n] = t.l - t.t;
TP.push_back({ X[n],n });
}
void Calc2(int nd) {
while (PV[nd] < chk[nd].size() && chk[nd][PV[nd]])PV[nd]++;
if (PV[nd] == chk[nd].size()) {
MM[nd] = { INF,0 };
return;
}
auto it = Set[nd].lower_bound({ PV[nd],0ll });
if (it == Set[nd].end()) {
MM[nd] = { INF,0 };
return;
}
MM[nd] = { it->second, Num[nd][PV[nd]] };
}
void UDT(int nd, int b, int e) {
IT[nd] = MM[nd];
if (b == e)return;
IT[nd] = min(IT[nd], min(IT[nd * 2], IT[nd * 2 + 1]));
}
void Build(int nd, int b, int e, int dep) {
int i;
vector<pii>V;
for (i = b; i <= e; i++) V.push_back({ w[i].y,w[i].num });
sort(V.begin(), V.end());
int sz = V.size();
YY[nd].resize(sz);
chk[nd].resize(sz);
Num[nd].resize(sz);
PV[nd] = 0;
for (i = 0; i < sz; i++)chk[nd][i] = 0;
for (i = 0; i < sz; i++) {
YY[nd][i] = V[i].first;
Num[nd][i] = V[i].second;
Loc[V[i].second][dep] = i;
}
MM[nd] = IT[nd] = { INF,0 };
if (b == e)return;
int m = (b + e) >> 1;
Build(nd * 2, b, m, dep + 1);
Build(nd * 2 + 1, m + 1, e, dep + 1);
UDT(nd, b, e);
}
void init() {
sort(X + 1, X + n + 1);
sort(TP.begin(), TP.end());
int cc = 0;
for (auto &t : TP) {
int x = t.second;
w[++cc] = { Y[x],x };
ReNum[x] = cc;
}
Build(1, 1, n, 0);
}
void Del2(int nd, int b, int e, int x, int dep) {
if (Loc[x][dep] >= chk[nd].size()) {
while (1) {}
}
chk[nd][Loc[x][dep]] = 1;
Calc2(nd);
if (b != e) {
int m = (b + e) >> 1;
if (ReNum[x] <= m)Del2(nd * 2, b, m, x, dep + 1);
else Del2(nd * 2 + 1, m + 1, e, x, dep + 1);
}
UDT(nd, b, e);
}
void Del(int a) {
Del2(1, 1, n, a, 0);
}
void Put2(int nd, int y, long long g) {
int pv = lower_bound(YY[nd].begin(), YY[nd].end(), y + 1) - YY[nd].begin();
if (!pv)return;
pv--;
auto it = Set[nd].lower_bound({ pv,-1ll });
if (it != Set[nd].end() && it->second <= g)return;
if (it != Set[nd].end() && it->first == pv)Set[nd].erase(it);
Set[nd].insert({ pv,g });
it = Set[nd].find({ pv,g });
while (it!=Set[nd].begin()) {
auto it2 = it; it2--;
if (it2->second >= g)Set[nd].erase(it2);
else break;
}
}
void Put(int nd, int b, int e, int s, int l, int y, long long g, int dep) {
if (s > l)return;
if (s <= b && e <= l) {
Put2(nd, y, g);
Calc2(nd);
UDT(nd, b, e);
return;
}
int m = (b + e) >> 1;
if (s <= m)Put(nd * 2, b, m, s, l, y, g, dep + 1);
if (l > m)Put(nd * 2 + 1, m + 1, e, s, l, y, g, dep + 1);
UDT(nd, b, e);
}
void Ins(int x, int y, long long g) {
int pv = lower_bound(X + 1, X + n + 1, x + 1) - X;
pv--;
Put(1, 1, n, 1, pv, y, g, 0);
}
}T;
void Insert(int a) {
T.Ins(P[a].r+1 + P[a].t, P[a].r+1 - P[a].t, D[a]);
T.Del(a);
}
int main() {
//freopen("input.txt", "r", stdin);
int i, j;
scanf("%d%d", &L, &n);
T.n = 0;
for (i = 1; i <= n; i++) {
scanf("%d%d%d%d", &P[i].t, &P[i].l, &P[i].r, &P[i].c);
T.Add(P[i], i);
D[i] = INF;
}
T.init();
for (i = 1; i <= n; i++) {
if (P[i].l == 1) {
D[i] = P[i].c;
Insert(i);
}
}
while (1) {
pli tp = T.IT[1];
if (tp.first > 1e17)break;
D[tp.second] = tp.first + P[tp.second].c;
Insert(tp.second);
}
long long res = INF;
for (i = 1; i <= n; i++) {
if (P[i].r == L)res = min(res, D[i]);
}
if (res > 1e17)res = -1;
printf("%lld\n", res);
}
