#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

void solve() {
    ll n;
    cin >> n;
    string S;
    cin >> S;
    std::map<char, long long> als;
    for (char c = 'A'; c <= 'Z'; ++c) {
        als[c] = 0;
    }

    for (ll i = 0; i < n; ++i) {
        als[S[i]]++;
    }

    // sort(S. begin(), S.  end());

    for (auto a : als) {
        cout << a.second;
    }

    cout << endl;
}

int main() {
    solve();
    return 0;
}