// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/

#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
#define int long long
#define ld long double
#define pii pair<int,int>
#define piii pair<int,pii>
#define mpp make_pair
#define fi first
#define se second
const int inf=1e18;
const int mod=998244353;
const int maxn=200005;
const int bl=650;
const int maxs=655;
const int maxm=200005;
const int maxq=1000005;
const int maxl=20;
const int maxa=1000000;
const int root=3;
int power(int a,int n){
    int res=1;
    while(n){
        if(n&1) res=res*a%mod;
        a=a*a%mod;n>>=1;
    }
    return res;
}

const int iroot=power(3,mod-2);
const int base=101;

struct pt{
    int x,y;
    pt operator + (const pt &p)const{
        return pt{x+p.x,y+p.y};
    }
    pt operator - (const pt &p)const{
        return pt{x-p.x,y-p.y};
    }
    int operator *(const pt &p)const{
        return x*p.y-y*p.x;
    }
    friend bool operator<(pt a,pt b){return make_pair(a.y,a.x)<make_pair(b.y,b.x);}
    friend bool operator>(pt a,pt b){return make_pair(a.y,a.x)>make_pair(b.y,b.x);}
    friend bool operator==(pt a,pt b){return make_pair(a.y,a.x)==make_pair(b.y,b.x);}
};
void reorder(vector<pt> &P){
    int pos=0;
    for(int i=1;i<(int)P.size();i++)
        if(P[i].y<P[pos].y || (P[i].x<P[pos].x && P[i].y==P[pos].y)) pos=i;
    rotate(P.begin(),P.begin()+pos,P.end());
}
vector<pt> minkowski(vector<pt> &P,vector<pt> &Q){
    reorder(P);reorder(Q);
    P.push_back(P[0]);P.push_back(P[1]);
    Q.push_back(Q[0]);Q.push_back(Q[1]);
    vector<pt> res;
    int i=0,j=0;
    while(i<(int)P.size()-2 || j<(int)Q.size()-2){
        res.push_back(P[i]+Q[j]);
        int cross=(P[i+1]-P[i])*(Q[j+1]-Q[j]);
        if(cross>=0 && i<(int)P.size()-2) i++;
        if(cross<=0 && j<(int)Q.size()-2) j++;
    }
    return res;
}
vector<pt> convex_hull(vector<pt> p){
    sort(p.begin(),p.end());
    p.erase(unique(p.begin(),p.end()),p.end());
    pt st=p[0],en=p.back();
    vector<pt> up,dn;
    for(int i=0;i<(int)p.size();i++){
        int o=(en-st)*(p[i]-st);
        if(o>=0){
            while((int)up.size()>=2 && (up.back()-up[(int)up.size()-2])*(p[i]-up[(int)up.size()-2])>=0) up.pop_back();
            up.push_back(p[i]);
        }
        if(o<=0){
            while((int)dn.size()>=2 && (dn.back()-dn[(int)dn.size()-2])*(p[i]-dn[(int)dn.size()-2])<=0) dn.pop_back();
            dn.push_back(p[i]);
        }
    }
    for(int i=(int)up.size()-2;i>=1;i--) dn.push_back(up[i]);
    return dn;
}
int n,m,sa,sb,res=inf;
vector<pair<int,pt>> edge[maxn];
vector<pt> ans,cur;

pt pu[maxn];
int par[maxn],dep[maxn];

void dfs(int u,int p){
    dep[u]=dep[p]+1;par[u]=p;
    for(auto [v,w]:edge[u]){
        if(!dep[v]){
            pu[v]=w;
            dfs(v,u);
        }
    }
}

void solve(){
    cin >> n >> m;
    for(int i=1;i<=m;i++){
        int u,v,a,b;cin >> u >> v >> a >> b;
        edge[u].push_back({v,{a,b}});
        edge[v].push_back({u,{a,b}});
        sa+=a;sb+=b;
    }
    dfs(1,0);
    for(int i=1;i<=n;i++){
        int u=-1;cur.clear();
        for(auto [v,w]:edge[i]){
            if(dep[v]<dep[i]) cur.push_back(w),u=v;
        }
        if(u!=-1){
            int cc=i;
            while(cc!=u){
                cur.push_back(pu[cc]);
                cc=par[cc];
            }
            cur=convex_hull(cur);
            if(ans.empty()) ans=cur;
            else ans=minkowski(ans,cur);
        }
    }
    for(pt d:ans) res=min(res,(sa-d.x)*(sb-d.y));
    cout << res << '\n';
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);cout.tie(NULL);
    int test=1;//cin >> test;
    while(test--) solve();

}