#include<bits/stdc++.h>
#define ll long long
const int nmax = 1e5 + 5, N = 1e5;
const ll oo = 1e18 + 5, base = 311;
const int lg = 17,mod = 1e9 +7;
#define pii pair<ll, ll>
#define fi first
#define se second
#define endl "\n"
#define debug(a, n) for(int i = 1; i <= n; ++i) cout << a[i] << ' '; cout << "\n";
using namespace std;
int n, m;
struct node{
ll t, l, r, c;
}a[nmax];
ll dp[nmax];
ll tree[nmax << 2][2];
priority_queue<pii, vector<pii>, greater<pii>> q;
void build(int id, int l, int r){
if(l == r){
if(dp[l] == oo){
tree[id][0] = a[l].l - a[l].t;
tree[id][1] = a[l].l + a[l].t;
}
else tree[id][0] =tree[id][1] = oo;
return;
}
int mid = r+ l >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
for(int e = 0; e < 2; ++e) tree[id][e] = min(tree[id << 1][e], tree[id << 1 | 1][e]);
}
void update(int id, int l, int r, int u, int v,ll val, int k, int idx){
if(l > v || r < u || u > v)return;
if(tree[id][idx] > k) return;
if(l == r){
dp[l] = val + a[l].c;
// cout << l << ' ' << dp[l] << endl;
q.push({dp[l], l});
tree[id][0] = tree[id][1] = oo;
return;
}
int mid = r+ l >> 1;
update(id << 1, l, mid, u,v ,val, k, idx);
update(id << 1 | 1, mid + 1, r, u, v,val, k, idx);
for(int e = 0; e < 2; ++e) tree[id][e] = min(tree[id << 1][e], tree[id << 1 | 1][e]);
}
main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
// freopen("ROBOT.inp", "r", stdin);
// freopen("ROBOT.out", "w", stdout);
cin >> n >> m;
for(int i = 1; i <= m; ++i) cin >> a[i].t >> a[i].l >> a[i].r >> a[i].c;
sort(a + 1, a + 1 + m, [](node a, node b){
return a.t < b.t;
});
for(int i = 1; i <= m; ++i) dp[i] = oo;
for(int i = 1; i <= m; ++i){
if(a[i].l == 1){
dp[i] = a[i].c;
q.push({dp[i], i});
}
}
build(1, 1, m);
while(q.size()){
pii tmp = q.top();q.pop();
int u = tmp.se;
ll val = tmp.fi;
update(1, 1, m, 1, u - 1, val, a[u].r - a[u].t + 1, 0);
update(1, 1, m, u + 1, n, val, a[u].r + a[u].t + 1, 1);
}
ll ans = oo;
for(int i = 1; i <= m; ++i){
if(a[i].r == n){
ans = min(ans, dp[i]);
}
}
if(ans == oo) cout << -1;
else cout << ans;
}
/*
3 3
899
*/
