#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<ull, ull> pull;
typedef pair<ll, ll> pii;
typedef pair<ld, ld> pld;
ll n;
ll a[300009];
vector<ll> g[300009];
ll sz[300009];
ll block[300009];
ll ans;
void findsize(ll v, ll p){
sz[v] = 1;
for(auto u : g[v]){
if(u == p || block[u])
continue;
findsize(u, v);
sz[v] += sz[u];
}
}
ll findcentroid(ll v, ll p, ll tot){
for(auto u : g[v]){
if(u == p || block[u])
continue;
if(sz[u] >= tot/2)
return findcentroid(u, v, tot);
}
return v;
}
map<ll, ll> mpp1;
map<ll, ll> mpp2;
void dp1(ll v, ll p, ll cur, ll bal){
cur += a[v];
if(bal < 0 && a[v] == 1)
bal += a[v];
if(a[v] == -1)
bal += a[v];
if(bal == 0 && cur >= 0)
mpp1[cur]++;
for(auto u : g[v]){
if(u == p || block[u])
continue;
dp1(u, v, cur, bal);
}
}
void dp2(ll v, ll p, ll cur, ll bal){
cur += a[v];
if(bal > 0 && a[v] == -1)
bal += a[v];
if(a[v] == 1)
bal += a[v];
if(bal == 0 && cur <= 0)
mpp2[cur]++;
for(auto u : g[v]){
if(u == p || block[u])
continue;
dp2(u, v, cur, bal);
}
}
void maincalc(ll v){
findsize(v, -1);
v = findcentroid(v, -1, sz[v]);
map<ll, ll> cur1;
map<ll, ll> cur2;
for(auto u : g[v]){
if(block[u])
continue;
dp1(u, v, 0, 0);
dp2(u, v, 0, 0);
//cout << v << " ----- " << u << "\n";
for(auto u : mpp1){
//cout << u.ff << " " << u.ss << "\n";
if(u.ff + a[v] < 0)
continue;
if(u.ff + a[v] == 0)
ans += u.ss;
ans += cur2[-(u.ff+a[v])]*u.ss;
}
for(auto u : mpp2){
if(u.ff + a[v] > 0)
continue;
if(u.ff + a[v] == 0)
ans += u.ss;
ans += cur1[-(u.ff+a[v])]*u.ss;
}
for(auto u : mpp1){
if(u.ff < 0)
continue;
cur1[u.ff] += u.ss;
}
for(auto u : mpp2){
if(u.ff > 0)
continue;
cur2[u.ff] += u.ss;
}
mpp1.clear();
mpp2.clear();
}
cur1.clear();
cur2.clear();
block[v] = 1;
for(auto u : g[v]){
if(block[u] == 0)
maincalc(u);
}
}
ll input(){
char c;
cin >> c;
if(c == '(')
return 1;
if(c == ')')
return -1;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
//freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
cin >> n;
for(ll i = 1; i <= n; ++i)
a[i] = input();
for(ll i = 1; i < n; ++i){
ll t1, t2;
cin >> t1 >> t2;
g[t1].pb(t2);
g[t2].pb(t1);
}
maincalc(1);
cout << ans << "\n";
}
