#include <bits/stdc++.h>
using namespace std;
#define int long long
const int inf = 2e18;
const int N = 1e6 + 15;
int n, m, a[N], sz[N];
pair <int, int> dp[N];
vector <int> g[N];
pair <int, int> ans = make_pair(0LL, 0LL);
bool used[N];
void dfs(int v, int p = -1) {
sz[v] = 1;
for(int to : g[v])
if(!used[to] && to != p) {
dfs(to, v);
sz[v] += sz[to];
}
}
int centroid(int v, int p, int n) {
for(int to : g[v])
if(!used[to] && to != p && sz[to] > n / 2)
return centroid(to, v, n);
return v;
}
inline bool ls(pair <int, int> x, pair <int, int> y) {
return x.first * y.second < x.second * y.first;
}
void calc(int v, int p) {
dp[v] = make_pair(a[v], 1LL);
for(int to : g[v]) {
if(!used[to] && to != p) {
calc(to, v);
pair <int, int> x = make_pair(a[v] * dp[to].first, 1LL + dp[to].second);
if(ls(x, dp[v])) {
dp[v] = x;
int c = __gcd(dp[v].first, dp[v].second);
if(c)
dp[v].first /= c, dp[v].second /= c;
}
}
}
}
void solve(int v) {
used[v] = true;
dfs(v);
multiset <pair <int, int> > is;
for(int to : g[v])
if(!used[to]) {
calc(to, v);
is.insert(dp[to]);
}
for(int to : g[v]) {
if(!used[to]) {
pair <int, int> x = dp[to];
is.erase(is.find(x));
if(!is.empty()) {
x.first *= is.begin()->first, x.second += is.begin()->second;
if(ans == make_pair(0LL, 0LL) || ls(x, ans)) {
ans = x;
int c = __gcd(ans.first, ans.second);
if(c)
ans.first /= c, ans.second /= c;
}
}
is.insert(dp[to]);
}
}
for(int to : g[v])
if(!used[to])
solve(centroid(to, v, sz[to]));
}
#undef int
int main() {
#define int long long
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
for(int i = 1; i < n; ++i) {
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
for(int i = 1; i <= n; ++i) {
cin >> a[i];
pair <int, int> x = {a[i], 1LL};
if(ans == make_pair(0LL, 0LL) || a[i] < ans.first)
ans = x;
}
dfs(1, -1);
solve(centroid(1, -1, n));
cout << ans.first << '/' << ans.second << endl;
return 0;
}
