/*-----------------------------
Author : TgX.2
11Ti - K28 - CHV
-----------------------------*/
#include <bits/stdc++.h>
#define FOR(i, a, b) for (__typeof(b) i = (a) - ((a) >= (b)) + 1 * ((a) >= (b)); i != (b) - ((a) >= (b)) + 1 * ((a) < (b)); i += 1 - 2 * ((a) >= (b)))
#define FORC(i, a, b, c) for (__typeof(b) i = (a), _b = (b), _c = (c); i <= _b; i += _c)
#define FORSq(i, a, b) for (__typeof(b) i = (a), _b = (b); i * i <= _b; ++i)
#define FORSt(i, s) for (int i = 0, _s = (int)(s.size()); i < _s; ++i)
#define fi first
#define se second
#define pb push_back
#define len(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()
#define _ << " " <<
#define __ << "\n"
#define ___ << " "
#define file "temp"
#define ______________TgX______________ main()
#define int long long
#define intmax 1e9
#define intmin -1e9
#define llongmax 1e18
#define llongmin -1e18
#define memo(a, val) memset((a), (val), sizeof((a)))
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vpii;
#define arr(element_type, cnt) array<element_type, (cnt)>
#define db(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); cout << endl; }
void err(istream_iterator<string> it) {}
template<typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
cout << "[ " << *it << " = " << a << " ] ";
err(++it, args...);
}
template<typename T1, typename T2> ostream& operator << (ostream& out, const pair<T1, T2>& p) {
return out << "[ " << p.first << " , " << p.second << " ] ";
}
template<class Con, class = decltype(begin(declval<Con>()))>
typename enable_if<!is_same<Con, string>::value, ostream&>::type
operator << (ostream& out, const Con& con) {
out << "{ ";
for (auto beg = con.begin(), it = beg; it != con.end(); it++) {
out << (it == beg ? "" : ", ") << *it;
}
return out << " } ";
}
template<typename T1, typename T2>
bool mini(T1 &a, T2 b)
{if (a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2>
bool maxi(T1 &a, T2 b)
{if (a < b) a = b; else return 0; return 1;}
/*-----------------------------*/
const int maxn = 2e5 + 7;
int n, a[maxn], b[maxn];
vector<array<int, 2>> g[maxn];
struct LCA {
vector<int> euler, h, d;
vector<vector<int>> st;
int timer = 0;
void dfs(int u, int cnt) {
d[u] = euler.size();
euler.push_back(u);
h[u] = cnt;
for (auto val : g[u]) {
if (h[val[0]] == -1) {
dfs(val[0], cnt + 1);
euler.push_back(u);
}
}
}
#define mmin(x, y) (h[x] < h[y]) ? x : y
void buildSparseTable() {
int m = euler.size();
st.assign(m, vector<int>(20));
for (int i = 0; i < m; i++)
st[i][0] = euler[i];
for (int j = 1; (1 << j) <= m; j++)
for (int i = 0; i + (1 << j) - 1 < m; i++)
st[i][j] = mmin(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
}
int query(int l, int r) {
int j = __lg(r - l + 1);
return mmin(st[l][j], st[r - (1 << j) + 1][j]);
}
int lca(int u, int v) {
int left = d[u];
int right = d[v];
if (left > right) swap(left, right);
return query(left, right);
}
LCA(int n) : h(n + 7, -1), d(n + 7) {
dfs(1, 0);
buildSparseTable();
}
};
int cntt[maxn], cnt[maxn], dp[maxn];
void dfs(int u, int pre, int id) {
dp[u] = cntt[u];
for(auto val : g[u]) {
int v = val[0], idx = val[1];
if(v == pre) continue;
dfs(v, u, idx);
dp[u] += dp[v];
}
if (id != -1) cnt[id] = dp[u];
}
void process() {
cin >> n;
FOR(i, 1, n - 1) {
int u, v; cin >> u >> v >> a[i] >> b[i];
g[u].pb({v, i});
g[v].pb({u, i});
}
LCA lca(n);
FOR(i, 2, n) {
int k = lca.lca(i, i - 1);
// cout << i _ i - 1 _ k __ ;
cntt[i]++;
cntt[i - 1]++;
cntt[k] -= 2;
}
dfs(1, -1, -1);
// FOR(i, 1, n)
// cout << cnt[i] << " ";
int ans = 0;
FOR(i, 1, n - 1) {
ans += min(a[i] * cnt[i], b[i]);
}
cout << ans;
}
/*-----------------------------*/
______________TgX______________ {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (fopen(file".inp", "r")) {
freopen(file".inp", "r", stdin);
freopen(file".out", "w", stdout);
freopen(file".debug", "w", stderr);
}
process();
}
/*==============================+
|INPUT |
--------------------------------|
================================+
|OUTPUT |
--------------------------------|
===============================*/
