///#pragma GCC optimize("Ofast,unroll-loops")
///#pragma GCC target("avx,avx2,sse,sse2")
#include<bits/stdc++.h>
///#define int long long
#define ll long long
#define down cout<<'\n';
#define NHP ios_base::sync_with_stdio(0);cout.tie(0);cin.tie(0);
#define modwwe int t;cin>>t; while(t--)
#define bit(i,j) (i>>j&1)
#define sobit(a) __builtin_popcountll(a)
#define task "test"
#define fin(x) freopen(x".inp","r",stdin)
#define fou(x) freopen(x".out","w",stdout)
#define pb push_back
#define checktime cerr << (double)clock() / CLOCKS_PER_SEC * 1000 << " ms";
using namespace std;
void phongbeo();
const int mod2=998244353;
const int mod1=998244353;
struct icd
{
int a,b;
};
struct ib
{
int a;
int b;
};
struct ic
{
int a,b,c;
};
struct id
{
int a,b,c,d;
};
struct ie
{
int a,b,c, d,e,f;
};
int n,m,s1,s2,s4,s3,sf,k,r,mid,s5,s6,mx,s7,s8,s9,mx2,res,dem2=0,dem=0,l;
int i,s10,s12;
int el=29;
ll ss3;
main()
{
#ifndef ONLINE_JUDGE
///fin(task),fou(task);
#endif
NHP
/// cin>>s1;
/// modwwe
phongbeo();
}
struct cmp
{
bool operator()(ib a,ib b)
{
return a.b>b.b;
}
};
bool color[100001];
int dp[100001];
int dp2[200001];
priority_queue<ib,vector<ib>,cmp>p;
vector<ic> v[100001];
void phongbeo()
{
cin>>n>>m;
for(int i=1;i<=m;i++)
{
cin>>l>>r>>s2>>s3;
v[l].pb({r,s2,s3});
v[r].pb({l,s2,s3});
}
p.push({1,0});
for(int i=1;i<=n;i++)
dp[i]=1e18;
for(int i=1;i<=m;i++)
dp2[i]=1e18;
dp[1]=0;
while(!p.empty())
{
ib u=p.top();
p.pop();
if(u.a==n){cout<<u.b; exit(0);}
if(color[u.a]) continue;
color[u.a]=1;
dp[u.a]=u.b;
for(auto x:v[u.a])
{
dp2[x.b]=min(dp2[x.b],dp[x.a]);
dp2[x.b]=min(dp2[x.b],u.b);
}
for(auto x:v[u.a])
{
dp2[x.b]+=x.c;
}
for(auto x:v[u.a])
{
p.push({x.a,u.b+x.c});
if(dp2[x.b]<=1e18&&color[x.a]==0){
p.push({x.a,dp2[x.b]-x.c});
}
}
for(auto x:v[u.a])
dp2[x.b]=1e18;
}
cout<<-1;
}
