#include <cstdio>
#include <iostream>
#include <cmath>
#include <cstring>
#include <algorithm>
#define N 200005
#define fo(i,a,b) for (int i=a;i<=b;i++)
#define fd(i,a,b) for (int i=a;i>=b;i--)
#define INF 214748364using namespace std;
int Final[N],n,m;
int dis[N],d[N],Pre[N];
bool Flag[N];struct node
{int to,next,time;node(void){}node(int a,int b,int c) : to(a),next(b),time(c){}
};struct Q
{node Line[N];int Final[N],tot;
}e,e2;int read(int &n)
{char ch = ' ';int q = 0, w = 1;for (;(ch != '-') && ((ch < '0') || (ch> '9'));ch = getchar());if (ch == '-') w = -1,ch = getchar();for (; ch >= '0' && ch <= '9';ch = getchar()) q = q * 10 + ch - 48;n = q * w;return n;
}void Link(Q &e,int x,int y,int z)
{e.Line[++ e.tot] = node(y,e.Final[x],z),e.Final[x] = e.tot;
}void Spfa(Q &e)
{int l = 0 ,r = 1;    d[1] = 1;Flag[1] = true;while (l < r){int x = d[++ l];for (int i = e.Final[x];i;i = e.Line[i].next){int k = e.Line[i].to;if (dis[x] + e.Line[i].time < dis[k]){dis[k] = dis[x] + e.Line[i].time;if (x == 1) Pre[k] = k; else Pre[k] = Pre[x];if (!Flag[k]){Flag[k] = true;d[++ r] = k; }   }}Flag[x] = false;}
}int main()
{read(n);read(m);fo(i,1,m){int s,t,v,w;read(s),read(t),read(v),read(w);Link(e,s,t,v);Link(e,t,s,w);}    fo(i,1,n) dis[i] = INF;dis[1] = 0;Spfa(e);fo(i,1,n){int x = i;for (int k = e.Final[x];k;k = e.Line[k].next){int y = e.Line[k].to;if (y == 1){if (Pre[x] == x) Link(e2,x,n + 1,e.Line[k].time);else Link(e2,1,n+1,dis[x] + e.Line[k].time);}elseif (x == 1){if (Pre[y] != y) Link(e2,1,y,e.Line[k].time);}elseif (Pre[y] == Pre[x]) Link(e2,x,y,e.Line[k].time);else Link(e2,1,y,dis[x] + e.Line[k].time); }}fo(i,1,n + 1) dis[i] = INF;dis[1] = 0;Spfa(e2);if (dis[n + 1] == INF) printf("-1\n");else printf("%d\n",dis[n + 1]);return 0;
}