#include <cstdio>
#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
const int M = 100005;
#define int long long
const int inf = 1e18;
int read()
{
	int x=0,f=1;char c;
	while((c=getchar())<'0' || c>'9') {if(c=='-') f=-1;}
	while(c>='0' && c<='9') {x=(x<<3)+(x<<1)+(c^48);c=getchar();}
	return x*f;
}
int n,m,ans,f[M],mn[4*M][2];
struct node
{
	int t,l,r,c;
	bool operator < (const node &b) const
	{
		return t<b.t;
	}
}a[M];
struct data
{
	int u,c;
	bool operator < (const data &b) const
	{
		return c>b.c;
	}
};priority_queue<data> q;
void up(int i)
{
	mn[i][0]=min(mn[i<<1][0],mn[i<<1|1][0]);
	mn[i][1]=min(mn[i<<1][1],mn[i<<1|1][1]);
}
void ins(int i,int l,int r,int id,int x,int v)
{
	if(l==r)
	{
		mn[i][0]=x-v;
		mn[i][1]=x+v;
		return ;
	}
	int mid=(l+r)>>1;
	if(mid>=id) ins(i<<1,l,mid,id,x,v);
	else ins(i<<1|1,mid+1,r,id,x,v);
	up(i);
}
void ask(int i,int l,int r,int L,int R,int op,int v,int w)
{
	if(l>R || L>r || mn[i][op]>v) return ;
	if(l==r)
	{
		f[l]=w+a[l].c;q.push(data{l,f[l]});
		mn[i][0]=mn[i][1]=inf;
		return ;
	}
	int mid=(l+r)>>1;
	ask(i<<1,l,mid,L,R,op,v,w);
	ask(i<<1|1,mid+1,r,L,R,op,v,w);
	up(i);
}
signed main()
{
	n=read();m=read();ans=inf;
	for(int i=1;i<=m;i++)
	{
		f[i]=inf;
		a[i].t=read();a[i].l=read();
		a[i].r=read();a[i].c=read();
	}
	sort(a+1,a+1+m);
	for(int i=1;i<=m;i++)
	{
		if(a[i].l==1)
		{
			f[i]=a[i].c;
			q.push(data{i,f[i]});
			ins(1,1,m,i,inf,0);
		}
		else ins(1,1,m,i,a[i].l,a[i].t);
	}
	while(!q.empty())
	{
		int u=q.top().u;q.pop();
		ask(1,1,m,1,u-1,0,a[u].r-a[u].t+1,f[u]);
		ask(1,1,m,u+1,m,1,a[u].r+a[u].t+1,f[u]);
	}
	for(int i=1;i<=m;i++)
		if(a[i].r==n)
			ans=min(ans,f[i]);
	if(ans==inf) puts("-1");
	else printf("%lld\n",ans);
}