#include <iostream>
#include<vector>
#include<set>
#include<map>
#include<fstream>
#include<algorithm>
using namespace std;
#define ll long long
#define pi pair<ll,ll>
#define x first
#define y second
#define vi vector<int>
#define all(v) v.begin(),v.end()
#define l x.x
#define r x.y
#define t y.x
#define p y.y
#define maxn (1<<17)
#define maxs (1<<18)
ll min(ll a, ll b) { return a < b ? a : b; }
ll ab(ll n) { return n > 0 ? n : -n; }
vector<int> le(maxs), ri(maxs);
vector<set<pi>> v(maxs);
void bld() {
for (int i = maxn; i < maxs; i++) {
le[i] = ri[i] = i - maxn;
}
for (int i = maxn - 1; i > 0; i--) {
le[i] = le[i << 1];
ri[i] = ri[(i << 1) + 1];
}
}
void insert(int i, int j, int ind) {
//cout << i << ' ' << j << ' ' << ind << endl;
i = 2 * (i + maxn);
while (i >>= 1) v[i].insert({j, ind});
}
void del(int i, int j, int ind) {
i = 2 * (i + maxn);
while (i >>= 1) v[i].erase(v[i].find({ j, ind }));
}
void que(int i, int ex, int ey,vi&res) {
if (le[i] > ex) return;
if (ri[i] <= ex) {
//for (auto it : v[i]) {cout << it.x << ' ' << it.y << " ";}cout << endl;
for (auto it : v[i]) {
if (it.x > ey) break;
res.push_back(it.y);
}
}
else {
que(i << 1, ex, ey, res);
que((i << 1)+1, ex, ey, res);
}
}
int s, n;
long long func(int S, int N, vector<int> T, vector<int> L, vector<int> R, vector<int> P) {
s = S; n = N;
bld();
//N <= 5000
//vector<pair<pi, pi>> vec(n);
//for (int i = 0; i < n; i++) vec[i] = { {L[i],R[i]}, {T[i],P[i]} };
map<int, int> mp;
for (int i = 0; i < n; i++) mp[L[i] - T[i]] = 0;
int c = 0;
for (auto it : mp) mp[it.x] = c++;
//vector<ll> dist(n, 1e18);
//for (int i = 0; i < n; i++) if (L[i] == 1) dist[i] = P[i];
ll res = 1e18;
set<pair<ll, int>> st;
for (int i = 0; i < n; i++) {
if (L[i] == 1) st.insert({ P[i],i });
else insert(mp[L[i]-T[i]],L[i]+T[i],i);
}
while (st.size()) {
auto it = st.begin();
int i = it->y;
ll dst = it->x;
st.erase(it);
//cout << i << ' ' << dst << endl;
if (R[i] == s) res = min(res, dst);
auto lt = mp.upper_bound(R[i] - T[i] + 1);
if (lt == mp.begin()) continue;
lt--;
int u = lt->y;
//cout << u << endl;
vector<int> vec;
que(1, u, R[i]+T[i]+1, vec);
//cout << "vec: "; for (int j : vec) cout << j << ' '; cout << endl;
for (int j : vec) {
st.insert({ dst + P[j],j });
del(mp[L[j] - T[j]], L[j] + T[j], j);
}
/*for (int j = 0; j < n; j++) {
if (R[i] - T[i] + 1 >= L[j] - T[j] && R[i] + T[i] + 1 >= L[j] + T[j]) {
if (dist[j] > P[j] + dst) {
st.erase(st.find({ dist[j],j }));
dist[j] = P[j] + dst;
st.insert({ dist[j],j });
}
}
}*/
}
//ll res = 1e18;
//for (int i = 0; i < n; i++) if (R[i] == s && dist[i] < res) res = dist[i];
return res == 1e18 ? -1 : res;
/*map<int, ll> mp;
vector<pair<pi, pi>> vec(n);
for (int i = 0; i < n; i++) vec[i] = { {L[i],R[i]}, {T[i],P[i]} };
sort(all(vec));
mp[s + 1] = 0;
for (int i = n - 1; i >= 0; i--) {
auto it = mp.upper_bound(vec[i].r + 1);
if (it != mp.begin()) {
it--;
if (mp.find(vec[i].l) == mp.end()) mp[vec[i].l] = vec[i].p + it->y;
else mp[vec[i].l] = min(mp[vec[i].l], vec[i].p + it->y);
auto it = mp.find(vec[i].l);
while (next(it) != mp.end() && it->y < next(it)->y) mp.erase(next(it));
}
}
if (mp.find(1) != mp.end()) return mp[1];
return -1;*/
}
void run_tests() {
string name = "03-00.txt";
for (int i = 1; i <= 18; i++) {
cout << "TEST " << i << endl;
name[3] = '0' + i / 10;
name[4] = '0' + i % 10;
ifstream fin("in/" + name);
ifstream fout("out/" + name);
int S, N;
fin >> S >> N;
vector<int> T(N), L(N), R(N), P(N);
for (int i = 0; i < N; i++) fin >> T[i] >> L[i] >> R[i] >> P[i];
ll u = func(S, N, T, L, R, P),u1;
fout >> u1;
if (u != u1) {
cout << i << endl;
cout << S << ' ' << N << endl;
cout << u << ' ' << u1 << endl;
//for (int i = 0; i < N; i++) cout << T[i] << ' ' << L[i] << ' ' << R[i] << ' ' << P[i] << endl;
return;
}
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
//run_tests();
//return 0;
int S, N;
cin >> S >> N;
vector<int> T(N), L(N), R(N), P(N);
for (int i = 0; i < N; i++) cin >> T[i] >> L[i] >> R[i] >> P[i];
cout << func(S, N, move(T), move(L), move(R), move(P)) << endl;
return 0;
}
/*
10 5
2 5 10 3
1 1 6 5
5 2 8 3
7 6 10 4
4 1 3 1
7
*/
