#include <iostream>
#include <algorithm>
#include <vector>
#include <deque>
#include <set>
#include <queue>
#include <cassert>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
using vpll = vector<pll>;
using vi = vector<int>;
using vll = vector<ll>;
using pii = pair<int, int>;
#define sz(x) int(x.size())
struct project
{
int T;
int L;
int R;
int C;
int I;
};
vector<project> P;
const int maxM = 200'000;
vi query_ans;
vi visited(maxM, 0);
const ll INF = 1'000'000'000'000'000'000LL;
vll dp(maxM, INF);
struct pos
{
int i;
};
bool operator < (pos A, pos B)
{
if(dp[A.i] == dp[B.i]) return A.i < B.i;
else return dp[A.i] < dp[B.i];
}
struct segtree
{
// deque<int> v[220'000];
vector<int> v[1 << 20];
segtree()
{
;
}
segtree(int L, int R)
{
;
}
void add(int i, int l, int r, int I, ll Pr)
{
v[i].push_back(Pr);
if(l != r)
{
if(I <= (l+r)/2) add(2*i, l, (l+r)/2, I, Pr);
else add(2*i + 1, (l+r)/2+1, r, I, Pr);
}
}
void getU(int i, int l, int r, int L, int R, int mxv)
{
if(R < l || r < L || R < L) return;
else if(L <= l && r <= R)
{
while(1)
{
if(v[i].empty()) break;
if(P[v[i].back()].L + P[v[i].back()].T > mxv) break;
if(!visited[v[i].back()])
{
query_ans.push_back(v[i].back());
visited[v[i].back()] = 1;
}
v[i].pop_back();
}
}
else
{
getU(2*i, l, (l+r)/2, L, R, mxv);
getU(2*i+1, (l+r)/2+1, r, L, R, mxv);
}
}
void getD(int i, int l, int r, int L, int R, int mxv)
{
if(R < l || r < L || R < L) return;
else if(L <= l && r <= R)
{
while(1)
{
if(v[i].empty()) break;
if(P[v[i].back()].L - P[v[i].back()].T > mxv) break;
if(!visited[v[i].back()])
{
query_ans.push_back(v[i].back());
visited[v[i].back()] = 1;
}
v[i].pop_back();
}
}
else
{
getD(2*i, l, (l+r)/2, L, R, mxv);
getD(2*i+1, (l+r)/2+1, r, L, R, mxv);
}
}
};
segtree U, D;
set<pos> tbv;
int ct = 0;
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N, M;
cin >> N >> M;
P = vector<project>(M);
for(int i = 0; i < M; i++) cin >> P[i].T >> P[i].L >> P[i].R >> P[i].C;
sort(P.begin(), P.end(), [] (project x, project y)
{
return x.T < y.T;
});
for(int i = 0; i < M; i++) P[i].I = i;
// cerr << "A\n";
// int ct = 0;
// cerr << "size of P = " << sz(P) << '\n';
sort(P.begin(), P.end(), [] (project x, project y)
{
// cerr << "callsort\n";
// if((++ct) % 10000 == 0) cerr << "sorting: " << ct << '\n';
return x.L + x.T < y.L + y.T;
});
// cerr << "pre add\n";
for(int i = 0; i < M; i++)
U.add(1, 0, M-1, P[i].I, P[i].I);
// cerr << "post add\n";
sort(P.begin(), P.end(), [] (project x, project y)
{
return x.L - x.T < y.L - y.T;
});
// cerr << "B\n";
for(int i = 0; i < M; i++)
D.add(1, 0, M-1, P[i].I, P[i].I);
for(int f = 0; f < (1 << 18); f++)
{
reverse(U.v[f].begin(), U.v[f].end());
reverse(D.v[f].begin(), D.v[f].end());
}
// while(1);
// cerr << "C\n";
sort(P.begin(), P.end(), [] (project x, project y)
{
return x.I < y.I;
});
for(int i = 0; i < M; i++)
{
if(P[i].L == 1)
{
dp[i] = P[i].C;
visited[i] = 1;
tbv.insert(pos{i});
}
}
// cerr << "D\n";
while(!tbv.empty())
{
int u = tbv.begin()->i;
tbv.erase(tbv.begin());
// cerr << "visiting " << u << ' ' << P[u].L << ' ' << P[u].R << '\n';
query_ans.clear();
U.getU(1, 0, M-1, u+1, M-1, P[u].R + P[u].T + 1);
D.getD(1, 0, M-1, 0, u-1, P[u].R - P[u].T + 1);
for(int v: query_ans)
{
// cerr << u << " -> " << v << '\n';
assert(P[v].L <= P[u].R + 1 - abs(P[u].T - P[v].T));
assert(dp[v] == INF);
dp[v] = dp[u] + P[v].C;
tbv.insert(pos{v});
}
}
// cerr << "E\n";
ll final_ans = INF;
for(int i = 0; i < M; i++)
if(P[i].R == N)
final_ans = min(final_ans, dp[i]);
if(final_ans >= INF) final_ans = -1;
cout << final_ans << '\n';
}
