#include<bits/stdc++.h>
#define N 400005
#define LL long long
#define int LL
#define SZ(x) ((LL)(x.size()))
using namespace std;
long long read(){
	long long q=0,w=1;
	char ch=getchar();
	while(ch>'9' || ch<'0'){if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){q=q*10+(ch-'0');ch=getchar();}
	return q*w;
}
void write(LL x){
	if(x<0){putchar('-');x=(-x);}
	if(x>9)write(x/10);
	putchar('0'+x%10);
}
void writeln(LL x){write(x);puts("");}
void writecs(LL x){write(x);putchar(' ');}

struct Edge{int u,v,a,b,w;}e[N];

int n,m,l,r;

namespace DSU{
	int fa[N],siz[N];
	int Find(int x){return x==fa[x]?x:fa[x]=Find(fa[x]);}
	bool Union(int x,int y){
		if((x=Find(x))==(y=Find(y)))return false;
		if(siz[x]>siz[y])swap(x,y);
		siz[fa[x]=y]+=siz[x];
		return true;
	}
}
using namespace DSU;

int solve(int x){
	int ans=0;
	for(int i=1;i<=m;i++)e[i].w=e[i].a+e[i].b*x;
	for(int i=1;i<=n;i++)siz[fa[i]=i]=1;
	sort(e+1,e+m+1,[](Edge x,Edge y){return x.w<y.w;});
	for(int i=1;i<=m;i++)
		if(Union(e[i].u,e[i].v))ans+=e[i].w;
	return ans;
}

signed main(){
	while(scanf("%d%d%d%d",&n,&m,&l,&r)!=EOF){
		for(int i=1;i<=m;i++)e[i].u=read(),e[i].v=read(),e[i].a=read(),e[i].b=read();
		printf("%lld\n",min(solve(l),solve(r)));
	}
	return 0;
}