#include <bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define debug(x) cerr << #x << " = " << (x) << ' '
#define bug(x) cerr << (x) << ' '
#define endl cerr << '\n'
#define all(v) (v).begin(), (v).end()
#define SZ(v) (ll)(v).size()
#define lowbit(x) (x)&-(x)
#define pb emplace_back
#define F first
#define S second
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
//#define TEST
string s, tmp;
set<string> st;
int main(void)
{ IO
int n, i;
cin >> n >> s, s = " " + s;
for (i=0; i < n-1; ++i)
{
int x, y; cin >> x >> y;
if (x != 1) assert(0);
tmp = s[x], st.insert(tmp);
tmp = s[y], st.insert(tmp);
tmp = s[x] + s[y], st.insert(tmp);
cout << SZ(st) << '\n';
}
return 0;
}
