#pragma GCC optimize("Ofast", "O3", "inline", "unroll-loops")
#include <bits/stdc++.h>
#define inf (0x7f7f7f7f)
#define Max(a, b) ((a) > (b) ? (a) : (b))
#define Min(a, b) ((a) < (b) ? (a) : (b))
typedef long long ll;
using namespace std;
#define fi first
#define se second
template <class T>
inline void read(T &x){
    int ch = 0, f = 0; x = 0;
    for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = 1;
    for(; isdigit(ch); ch = getchar()) x = x * 10 + ch - 48;
    if(f) x = -x;
}
const int N = 300005;
vector<vector<int> > groups;
vector<int> e[N], sta, esta;
pair<int, int> es[N];
int mark[N], a[N], b[N], dfn[N], low[N], n, m, idx;
inline void dfs(int u){
    dfn[u] = low[u] = ++idx;
    sta.push_back(u);
    for(auto ind : e[u]) if(!mark[ind]){
        mark[ind] = 1;
        esta.push_back(ind);
        auto [x, y] = es[ind];
        int v = u ^ x ^ y;
        if(!dfn[v]){
            dfs(v);
            low[u] = min(low[u], low[v]);
            if(low[v] >= dfn[u]){
                while(1){
                    int z = sta.back();
                    sta.pop_back();
                    if(z == v) break;
                }
                vector<int> vec;
                while(1){
                    int z = esta.back();
                    esta.pop_back();
                    vec.push_back(z);
                    if(z == ind) break;
                }
                groups.push_back(vec);
            }
        } 
        else low[u] = min(low[u], dfn[v]);
    }
}
vector<pair<ll, ll> >gethull(vector<int> vec){
    ll A = 0, B = 0;
    vector<pair<ll, ll> > res;
    if(vec.size() == 1){
        res.push_back(make_pair(a[vec[0]], b[vec[0]]));
        return res;
    }
    vector<pair<int, int> > tmp;
    
    tmp.clear(), res.clear();
    for(auto i : vec){
        A += a[i];
        B += b[i];
        tmp.push_back(make_pair(a[i], b[i]));
    }
    sort(tmp.begin(), tmp.end());
    reverse(tmp.begin(), tmp.end());
    int maxb = -1;
    for(auto [x, y] : tmp){
        if(y > maxb){
            maxb = y;
            res.push_back(make_pair(A - x, B - y));
        }
    }
    return res;
}
vector<pair<ll, ll> > merge(vector<pair<ll, ll> > a, vector<pair<ll, ll> > b){
    vector<pair<ll, ll> > res;
    for(int i = a.size() - 1; i >= 1; i--){
        a[i].fi = a[i].fi - a[i - 1].fi;
        a[i].se = a[i].se - a[i - 1].se;
    }
    for(int i = b.size() - 1; i >= 1; i--){
        b[i].fi = b[i].fi - b[i - 1].fi;
        b[i].se = b[i].se - b[i - 1].se;
    }
    res.push_back(make_pair(a[0].fi + b[0].fi, a[0].se + b[0].se));
    int i = 1, j = 1;
    while(i < a.size() && j < b.size()){
        if(a[i].se * b[j].fi >= b[j].se * a[i].fi){
            res.push_back(a[i++]);
        }
        else{
            res.push_back(b[j++]);
        }
    }
    while(i < a.size()) res.push_back(a[i++]);
    while(j < b.size()) res.push_back(b[j++]);
    for(int k = 1; k < res.size(); k++){
        res[k].fi += res[k - 1].fi;
        res[k].se += res[k - 1].se;
    }
    return res;
}
int main(){
    read(n), read(m);
    for(int i = 1, x, y; i <= m; i++){
        read(x), read(y);
        read(a[i]), read(b[i]);
        es[i] = {x, y};
        e[x].push_back(i);
        e[y].push_back(i);
    }
    dfs(1);
    priority_queue<pair<int, int> > pq;
    vector<vector<pair<ll, ll> > > hulls;
    for(auto vec : groups){
        hulls.push_back(gethull(vec));
        pq.push({-(int) hulls.back().size(), (int) hulls.size() - 1});
    }
    while((int) pq.size() > 1){
        auto [x, u] = pq.top(); pq.pop();
        auto [y, v] = pq.top(); pq.pop();
        hulls[u] = merge(hulls[u], hulls[v]);
        pq.push({-(int) hulls[u].size(), u});
    }
    auto[x, u] = pq.top();
    ll ans = 7e18;
    for(auto [A, B]: hulls[u]){
        ans = min(ans, A * B);
    }
    printf("%lld\n", ans);
    return 0;
}