1 //  2 //by coolxxx  3 //#include<bits/stdc++.h>  4 #include<iostream>  5 #include<algorithm>  6 #include<string>  7 #include<iomanip>  8 #include<map>  9 #include<stack> 10 #include<queue> 11 #include<set> 12 #include<bitset> 13 #include<memory.h> 14 #include<time.h> 15 #include<stdio.h> 16 #include<stdlib.h> 17 #include<string.h> 18 //#include<stdbool.h> 19 #include<math.h> 20 #define min(a,b) ((a)<(b)?(a):(b)) 21 #define max(a,b) ((a)>(b)?(a):(b)) 22 #define abs(a) ((a)>0?(a):(-(a))) 23 #define lowbit(a) (a&(-a)) 24 #define sqr(a) ((a)*(a)) 25 #define swap(a,b) ((a)^=(b),(b)^=(a),(a)^=(b)) 26 #define mem(a,b) memset(a,b,sizeof(a)) 27 #define eps (1e-8) 28 #define J 10000 29 #define mod 1000000007  30 #define MAX 0x7f7f7f7f 31 #define PI 3.14159265358979323 32 #define N 100004 33 #define M 200004 34 using namespace std; 35 typedef long long LL; 36 int cas,cass; 37 int n,m,lll,ans; 38 int last[N],q[N]; 39 LL aans; 40 bool u[N]; 41 set<int>c[N]; 42 map<int,LL>d[N]; 43 struct xxx 44 { 45     int next,to,dd,co; 46 }a[M]; 47 void add(int x,int y,int c,int z) 48 { 49     a[++lll].to=y; 50     a[lll].dd=z; 51     a[lll].co=c; 52     a[lll].next=last[x]; 53     last[x]=lll; 54 } 55 void spfa() 56 { 57     int i,j,k,now,to,l=0,r=1; 58     set<int>::iterator ii; 59     q[1]=1; 60     for(ii=c[1].begin();ii!=c[1].end();ii++)d[1][(*ii)]=0; 61     while(l!=r) 62     { 63         now=q[l=(l+1)%N]; 64         if(now==n)continue; 65         u[now]=0; 66         for(i=last[now];i;i=a[i].next) 67         { 68             to=a[i].to; 69             if(d[to].find(a[i].co)==d[to].end()) 70                 d[to][a[i].co]=MAX; 71             for(ii=c[now].begin();ii!=c[now].end();ii++) 72             { 73                 if(d[now].find((*ii))==d[now].end())continue; 74                 if(d[now][(*ii)]+a[i].dd+abs((*ii)-a[i].co)>aans)continue; 75                 if(d[now][(*ii)]+a[i].dd+abs((*ii)-a[i].co)<d[to][a[i].co]) 76                 { 77                     d[to][a[i].co]=d[now][(*ii)]+a[i].dd+abs((*ii)-a[i].co); 78                     if(to==n) 79                     { 80                         aans=min(aans,d[to][a[i].co]); 81                         continue; 82                     } 83                     if(!u[to]) 84                     { 85                         u[to]=1; 86                         q[r=(r+1)%N]=to; 87                     } 88                 } 89             } 90         } 91     } 92 } 93 int main() 94 { 95     #ifndef ONLINE_JUDGE 96 //    freopen("1.txt","r",stdin); 97 //    freopen("2.txt","w",stdout); 98     #endif 99     int i,j,k;100     int x,y,z;101 //    for(scanf("%d",&cass);cass;cass--)102 //    for(scanf("%d",&cas),cass=1;cass<=cas;cass++)103 //    while(~scanf("%s",s+1))104     while(~scanf("%d",&n))105     {106         for(i=1;i<=n;i++)107         {108             c[i].clear();109             d[i].clear();110         }111         mem(last,0);mem(u,0);lll=0;112         scanf("%d",&m);113         for(i=1;i<=m;i++)114         {115             scanf("%d%d%d%d",&x,&y,&j,&z);116             add(x,y,j,z);117             add(y,x,j,z);118             c[x].insert(j);c[y].insert(j);119         }120         aans=100000000000000;121         spfa();122         printf("%lld\n",aans);123     }124     return 0;125 }126 /*127 //128 129 //130 */