$record$

#include <bits/stdc++.h>
using namespace std;
//#pragma GCC optimize(2)
//#pragma GCC optimize(3, "Odpst", "inline")
#define hh putchar('\n')
#define kg putchar(' ')
#define debug puts("debug")
#define int long long
//#define int __int128
namespace quickread{
	template<typename T> void read(T &x){
		x=0;char c=getchar();T neg=0;
		while(!isdigit(c)) neg|=!(c^'-'),c=getchar();
		while(isdigit(c)) x=(x<<3)+(x<<1)+(c^48),c=getchar();
		if(neg) x=(~x)+1;
	}
	template<typename T> void write(T x){
		if(x<0) putchar('-'),x=~x+1;
		if(x>9) write(x/10);
		putchar(x%10^48);
	}
	inline string readstr(){
    	char ch=getchar();string str="";
		while(!isalnum(ch)) ch=getchar();
		while(isalnum(ch)){str+=ch;ch=getchar();}
		return str;
	}
	inline char readchar(){
		char ch=getchar();
		while(!isalnum(ch)) ch=getchar();
		return ch;
	}
}
using namespace quickread;
const int N=1e6+10,inf=2147483647;
int n,ans,val[N],dep[N],dp[N][50],lg[N];
struct edge{int v,w1,w2;};
vector <edge> tree[N];
void init(int u,int f){
	dep[u]=dep[f]+1;
	dp[u][0]=f;
	for(int i=1;i<=lg[dep[u]];i++)
		dp[u][i]=dp[dp[u][i-1]][i-1];
	for(edge to:tree[u]){
		int v=to.v;
		if(v^f) init(v,u);
	}

}
int lca(int x,int y){
	if(dep[x]<dep[y]) swap(x,y);
	while(dep[x]>dep[y]) x=dp[x][lg[dep[x]-dep[y]]-1];
	if(x==y) return y;
	for(int k=lg[dep[x]]-1;k>=0;k--)
		if(dp[x][k]!=dp[y][k]) x=dp[x][k],y=dp[y][k];
	return dp[x][0];
}
void dfs(int u,int f){
	for(edge to:tree[u]){
		int v=to.v;
		if(v^f) dfs(v,u),val[u]+=val[v];
	}
	for(edge to:tree[u]){
		int v=to.v,w1=to.w1,w2=to.w2;
		if(!(v^f))	ans+=min(w1*val[u],w2);
	}
}
signed main(){
//	ios::sync_with_stdio(0);
//	cin.tie(0);cout.tie(0);
	read(n);
	for(int i=1,u,v,w1,w2;i<n;++i){
		read(u),read(v),read(w1),read(w2);
		tree[u].push_back(edge{v,w1,w2});
		tree[v].push_back(edge{u,w1,w2});
	}
	init(1,0);
	for(int i=1;i<n;++i) val[i]++,val[i+1]++,val[lca(i,i+1)]-=2;
	dfs(1,0);
	write(ans);
	return 0;
}

``