#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <tuple>
typedef long long ll;
typedef std::pair<ll,ll> pr;
constexpr int N=50010,M=200010;
struct convex
{
	pr st;
	std::vector<pr> num;
};
convex merge(const convex &a,const convex &b)
{
	pr rst(a.st.first+b.st.first,a.st.second+b.st.second);
	std::vector<pr> seq;
	std::merge(a.num.begin(),a.num.end(),b.num.begin(),b.num.end(),std::back_inserter(seq),[](auto a,auto b){return a.second*b.first<b.second*a.first;});
	return (convex){rst,seq};
}
convex get_convex(std::vector<pr> a)
{
	std::sort(a.begin(),a.end(),[](auto a,auto b){return a.first<b.first || (a.first==b.first && a.second>b.second);});
	static pr stk[N];int top(0);
	for(auto v:a)
	{
		if(!top){stk[++top]=v;continue;}
		if(stk[top].first==v.first) --top;
		while(top>=2 && (v.second-stk[top].second)*(stk[top].first-stk[top-1].first)<=(stk[top].second-stk[top-1].second)*(v.first-stk[top].first)) --top;
		stk[++top]=v;
	}
	pr st(stk[1]);
	std::vector<pr> df;
	for(int i(2);i<=top;++i) df.emplace_back(stk[i].first-stk[i-1].first,stk[i].second-stk[i-1].second);
	return (convex){st,df};
}
std::vector<std::tuple<int,int,int>> es[N];
pr stk[N+M];int dfn[N],low[N],dcnt,top,bcnt;convex cs[N];
std::priority_queue<std::pair<int,int>> pq;
void tarjan(int u)
{
	dfn[u]=low[u]=++dcnt;stk[++top]={-1,u};
	for(auto [v,ai,bi]:es[u])
	{
		if(!dfn[v])
		{
			tarjan(v);
			if(low[v]==dfn[u])
			{
				pr val;
				std::vector<pr> res;ll ta=0,tb=0;
				do
				{
					val=stk[top--];
					if(~val.first) res.emplace_back(val),ta+=val.first,tb+=val.second;
				}
				while(!(val.first==-1 && val.second==v));
				if(res.size()!=1) for(auto &[va,vb]:res) va=ta-va,vb=tb-vb;
				cs[++bcnt]=get_convex(res);
				pq.emplace(-int(cs[bcnt].num.size()),bcnt);
			}
		}
		else if(dfn[v]<dfn[u])
		{
			stk[++top]={ai,bi};
			low[u]=std::min(low[u],dfn[v]);
		}
	}
}
int main()
{
	int n,m;std::ios::sync_with_stdio(false);std::cin.tie(0);
	std::cin>>n>>m;
	for(int i(1),u,v,a,b;i<=m;++i) std::cin>>u>>v>>a>>b,es[u].emplace_back(v,a,b),es[v].emplace_back(u,a,b);
	tarjan(1);
	for(int i(1);i<bcnt;++i)
	{
		auto [n1,v1]=pq.top();pq.pop();
		auto [n2,v2]=pq.top();pq.pop();
		cs[v1]=merge(cs[v1],cs[v2]);
		pq.emplace(n1+n2,v1);
	}
	int u=pq.top().second;
	auto [ta,tb]=cs[u].st;
	ll ans=ta*tb;
	for(auto [va,vb]:cs[u].num)
	{
		ta+=va;tb+=vb;
		ans=std::min(ans,ta*tb);
	}
	std::cout<<ans<<std::endl;
	return 0;
}