#include <bits/stdc++.h> 
using namespace std;
const int N=1010,M=1e6;
int read(){
	int x=0,f=1;
	char c=getchar();
	while(c<48||c>57){
		if(c==45) f=-1;
		c=getchar();
	}
	while(c>=48&&c<=57){
		x=x*10+c-48;
		c=getchar();
	}
	return f*x;
}
int n,m;
struct edge{
	int to,nxt,w,f;
}e[N<<1];
int h[N],tot;
void add(int u,int v,int w,int f){
	e[++tot].to=v;
	e[tot].nxt=h[u];
	e[tot].w=w;
	e[tot].f=f;
	h[u]=tot;
	return;
}
int dis[N];
int vis[N];
queue<int> q;
int spfa(int ff){
	memset(dis,0x3f,sizeof(dis));
	memset(vis,0,sizeof(vis));
	while(!q.empty()) q.pop();
	dis[1]=0;q.push(1);vis[1]=1;
	int u,v,w,f;
	while(!q.empty()){
		u=q.front();q.pop();
		for(int i=h[u];i;i=e[i].nxt){
			v=e[i].to;w=e[i].w;vis[v]=0;f=e[i].f;
			if(f<ff) continue;
			if(dis[v]>dis[u]+w){
				dis[v]=dis[u]+w;
				if(!vis[v]){
					vis[v]=1;
					q.push(v);
				}
			}
		}
	}
	return dis[n];
}
int ans;
double fen;
int main(){
	freopen("pump.in","r",stdin);
	freopen("pump.out","w",stdout);
	n=read();m=read();
	int u,v,w,f;
	for(int i=1;i<=m;i++){
		u=read();v=read();w=read();f=read();
		add(u,v,w,f);add(v,u,w,f);
	}
	int t;
	for(int i=1;i<=m*2;i+=2){
		f=e[i].f;
		t=spfa(f);
		fen=double(f)/double(t);
		fen*=M;
		ans=max(ans,int(fen));
	}
	printf("%d",ans);
	return 0;
}