#include <bits/stdc++.h>
using namespace std;
#define int ll
#define ll long long
#define pii pair<ll, ll>
#define f first
#define s second
#define SZ(x) (int)((x).size())
#define ALL(x) (x).begin(), (x).end()
#define pb push_back
#define MX(a,b) a = max(a,b)
#define MN(a,b) a = min(a,b)
#define FOR(i,a,b) for (int i = a; i<b; ++i)
#define REP(i,n) for (int i = 0; i<n; ++i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#ifdef BALBIT
#define bug(...) cerr<<"#"<<__LINE__<<"- "<<#__VA_ARGS__<<": ", _do(__VA_ARGS__)
template<typename T> void _do(T && x){cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T && x, S && ...y){cerr<<x<<", "; _do(y...);}
#else
#define bug(...)
#define endl '\n'
#endif // BALBIT
const int maxn = 3e5+5;
const int mod = 1e9+7;
const ll inf = 0x3f3f3f3f3f3f3f3f;
struct rect{
int x,y,r,c,i;
bool operator < (rect &R) {
if (y != R.y) return y < R.y;
return x < R.x;
}
};
bool isbeg[maxn], isend[maxn]; // for each rectangle, is it the beg or end?????
bool done[maxn];
ll dst[maxn];
ll get(vector<rect> v) {
for (rect &R : v) {
bug(R.x,R.y,R.r,R.c,R.i);
bug(isbeg[R.i]);
bug(isend[R.i]);
}
// sort(ALL(v));
memset(dst, 0x3f, sizeof dst);
int n = SZ(v);
for (rect &R : v) {
if (isbeg[R.i]) {
dst[R.i] = R.c;
}
}
ll re = inf;
REP(round, SZ(v)) {
int go = -1, mnd = inf;
REP(i,n) {
if (!done[i] && dst[i] < mnd) {
mnd = dst[i]; go = i;
}
}
if (go == -1) break;
done[go] = 1;
if (isend[go]) {
MN(re, mnd);
}
REP(j,n) {
if (!done[j]) {
// test if i can update him
if (v[go].x + v[go].r + 1 >= v[j].x &&
v[go].y + v[go].r + 1 >= v[j].y
) {
MN(dst[j], dst[go] + v[j].c);
}
}
}
}
if (re == inf) re = -1;
return re;
}
signed main(){
ios::sync_with_stdio(0), cin.tie(0);
bug(1,2);
vector<rect> go;
int n,m; cin>>n>>m;
REP(i,m) {
int t,l,r,c; cin>>t>>l>>r>>c;
--l; --r;
isbeg[i] = l == 0;
isend[i] = r == n-1;
go.pb({l+t, l-t,r-l,c,i});
}
ll re =get(go);
cout<<re<<endl;
}
/*
10 5
1 8 10 30
1 1 6 50
2 7 7 100
3 5 7 11
2 8 8 11
7 6 10 4
4 1 3 1
*/
