#include<bits/stdc++.h>
#define int long long
#define fr(i,j,k) for(register int i=j;i<=k;++i)
#define rf(i,j,k) for(register int i=j;i>=k;--i)
#define foredge(i,j) for(register int i=head[j];i;i=e[i].nxt)
#define pb push_back
#define Times printf("Time:%.3lf\n",clock()/CLOCKS_PER_SEC)
using namespace std;
inline int read(){
	int x=0;
	bool f=0;
	char c=getchar();
	while(!isdigit(c)) f|=(c=='-'),c=getchar();
	while(isdigit(c)) x=(x<<3)+(x<<1)+(c^48),c=getchar();
	return f?-x:x;
}
inline void write(int x){
    if(x<0){putchar('-');x=-x;}
    if(x>9)write(x/10);
    putchar(x%10+'0');
}
inline void writeln(int x){write(x); puts("");}
inline void writepl(int x){write(x); putchar(' ');}
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
inline int randfind(int l,int r){return rnd()%(r-l+1)+l;}
//inline void init(){
//	int t=read();
//	while(t--) work();
//}
const int Maxn=2e5+10;
struct edge{
    int x,y,a,b,z;
}ed[Maxn];
inline bool cmp(edge a,edge b){return a.z<b.z;}
int fa[Maxn];
inline int getfa(int x){
    if(fa[x]==x) return x;
    return fa[x]=getfa(fa[x]);
}
int n,m;
inline int getans(int p){
    fr(i,1,m) ed[i].z=ed[i].a+ed[i].b*p;
    sort(ed+1,ed+m+1,cmp);
    fr(i,1,n) fa[i]=i;
    int ans=0;
    fr(i,1,m){
        int x,y;
        x=ed[i].x,y=ed[i].y;x=getfa(x),y=getfa(y);
        if(x==y) continue;
        fa[getfa(x)]=y,ans+=ed[i].z;
    }
    return ans;
}
inline void work(){
    int l,r;l=read(),r=read();
    fr(i,1,m) ed[i].x=read(),ed[i].y=read(),ed[i].a=read(),ed[i].b=read();
    int ans=0;
    if(getans(l)<getans(r)) ans=l;
    else ans=r;
    writeln(getans(ans));
}
inline void init(){
    while(cin>>n>>m) work();
}
signed main(){
	// freopen("input.in","r",stdin);
	// freopen("output.out","w",stdout);
    init();
    // printf("\nTIME:%.3lf",(double)clock()/CLOCKS_PER_SEC);
	return 0;
}