#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int N=1e3+10,INF=0x3f3f3f3f;
int n,m;
vector<int> g[N];
vector<int> e[N];
vector<int> ef[N];
double ans=-9.9;
void dfs(int x,int end,int fm,int sum,int fa)
{
    if(x==end){
        double t=(fm*1.0)/(sum*1.0);
        ans=max(ans,t);
        return;
    }
    if(g[x].size()==1&&fa) return;
    for(int i=0;i<g[x].size();i++)
    {
        int y=g[x][i];
        if(y==fa) continue;
        fm=min(fm,ef[x][i]);
        sum+=e[x][i];
        dfs(y,end,fm,sum,x);
    }
}
int main()
{
    freopen("pump.in","r",stdin);
    freopen("pump.out","w",stdout);
    
    cin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,w,f;
        cin>>x>>y>>w>>f;
        g[x].push_back(y),e[x].push_back(w),ef[x].push_back(f);
        g[y].push_back(x),e[y].push_back(w),ef[y].push_back(f);
    }
    dfs(1,n,INF,0,0);
    ans=ans*1000000.0;
    printf("%.0f",ans);
    return 0;
}