#include<bits/stdc++.h>
#define lowbit(x) (x&(-x))
#define rep(x,a,b) for(int x=a;x<=b;x++)
#define pre(x,a,b) for(int x=a;x>=b;x--)
#define endl "\n"
#define pb push_back
#define ll long long
#define int long long
#define pii pair<ll,ll>
#define psi pair<string, ll>
#define de cout<<1;
#define mem(a,x) memset(a,x,sizeof a)
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
using namespace std;
const int mod1=998244353;
const int mod2=1e9+7;
const int INF=0x3f3f3f3f;
const int N = 1e6 + 60;
int n,m,number;
int par1[N],par2[N];
int idx1,idx2;
ll findd1(ll x)
{
	if(par1[x]!=x)par1[x]=findd1(par1[x]);
	return par1[x];
}
ll findd2(ll x)
{
	if(par2[x]!=x)par2[x]=findd2(par2[x]);
	return par2[x];
}
void init()
{
	rep(i,0,n)
	{
		par1[i]=i;
		par2[i]=i;
	}
}
struct node
{
	int a,b;
	int w;
}node1[N],node2[N];
bool cmp(node a,node b)
{
	return a.w<b.w;
}
void solve()
{
	int l,r;
	while(cin >> n >> m >> l >> r)
	{
		idx1=0,idx2=0;
		rep(i,1,m)
		{
			int a,b,x,y;
			cin >> a >> b >> x >> y;
			node1[idx1++]={a,b,x+l*y};
			node2[idx2++]={a,b,x+r*y};
		}
		sort(node1,node1+idx1,cmp);
		sort(node2,node2+idx2,cmp);
		init();
		int ans1=0,ans2=0;
		rep(i,0,idx1-1)
		{
			int fa=findd1(node1[i].a);
			int fb=findd1(node1[i].b);
			if(par1[fa]!=fb)
			{
				par1[fa]=fb;
				ans1+=node1[i].w;
			}
		}
		rep(i,0,idx2-1)
		{
			int fa=findd2(node2[i].a);
			int fb=findd2(node2[i].b);
			if(par2[fa]!=fb)
			{
				par2[fa]=fb;
				ans2+=node2[i].w;
			}
		}
		cout << min(ans1,ans2)<<endl;
	}

	
}
signed main()
{
	IOS;
	int _;
	//cin >> _;
	_ = 1;
	while(_ -- )
	{
		number++;
		solve();
	}
	return 0;
}