#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <unordered_map>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    const string t = "BSUIROPENX";

    unordered_map<string, int> dict;
    vector<string> data(n);
    for (int i = 0; i < n; ++i) {
        cin >> data[i];
    }
    int64_t ans = 0;
    for (auto&& s : data) {
        auto pos = t.find(s);
        if (pos == 0) {
            string for_search = t.substr(s.length());
            if (t.length() > s.length() && dict.find(for_search) != dict.end()) {
                ans += dict[for_search];
            }
            dict[s]++;
        } else if (t.find(s) == t.length() - s.length()) {
            string for_search = t.substr(0, t.length() - s.length());
            if (t.length() > s.length() && dict.find(for_search) != dict.end()) {
                ans += dict[for_search];
            }
            dict[s]++;
        }
    }
    cout << ans;
    return 0;
}