#define _USE_MATH_DEFINES
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include<bits/stdc++.h>
//#include<unordered_set>
//#include<random>
//#include <array>
//#include <complex>
//#include<chrono>
//#include<boost/multiprecision/cpp_int.hpp>
//#include <atcoder/all>
//using namespace boost::multiprecision;

using namespace std;
//using namespace atcoder;
#define LP(I,S,G) for (long long int I = (S); I < (G); ++I)
#define IN(X) 	for (int in = 0; in < X.size(); in++)cin >> X[in]
#define OUT(X) 	for (int in = 0; in < X.size(); in++)cout << X[in]<<" "
#define SORT(X) sort((X).begin(), (X).end())
#define CSORT(X,Y) sort(X.begin(), X.end(),Y)
#define COPY(X,Y) copy(X.begin(), X.end(), Y.begin())
#define ALL(X,Y) for (auto &(X) :(Y))
#define FULL(a)  (a).begin(),(a).end()
#define BFS(Q,S) for(Q.push(S);Q.size()!=0;Q.pop())
typedef long long int ll;
typedef unsigned long long int ull;
long long int M = 998244353;

chrono::system_clock::time_point starttime;
using namespace std::chrono;

inline float getTime() {
	return duration_cast<milliseconds>(system_clock::now() - starttime).count();
}


int dx[] = { -1,0,1,0 }, dy[] = { 0,1,0,-1 };

ll MAX(ll A, ll B) { return ((A) > (B) ? (A) : (B)); }
ll MIN(ll A, ll B) { return ((A) < (B) ? (A) : (B)); }
inline long long int xor128() {
	static long long int x = 123456789, y = 362436069, z = 521288629, w = 88675123;
	long long int t = (x ^ (x << 11));
	x = y; y = z; z = w;
	return (w = (w ^ (w >> 19)) ^ (t ^ (t >> 8)));
}

struct HashPair {

	//注意 constがいる
	template<class T1, class T2>
	size_t operator()(const pair<T1, T2>& p) const {

		//first分をハッシュ化する
		auto hash1 = hash<T1>{}(p.first);

		//second分をハッシュ化する
		auto hash2 = hash<T2>{}(p.second);

		//重複しないようにハッシュ処理
		size_t seed = 0;
		seed ^= hash1 + 0x9e3779b9 + (seed << 6) + (seed >> 2);
		seed ^= hash2 + 0x9e3779b9 + (seed << 6) + (seed >> 2);
		return seed;
	}
};

void get_comb_list(vector<vector<ll>>& r, ll s, ll rest, vector<ll> now = {}) {
	if (rest == 0) {
		reverse(now.begin(), now.end());
		r.push_back(now);
	}
	else {
		if (s == 0) return;
		get_comb_list(r, s - 1, rest, now);
		now.push_back(s - 1);
		get_comb_list(r, s - 1, rest - 1, now);
	}
}

int main() {
	ll n;
	cin >> n;
	string s;
	cin >> s;
	vector<vector<ll>> r;
	get_comb_list(r, n, 5);
	ll ans = 0;
	ALL(p, r) {
		string t;
		ALL(i, p)t += s[i];
		map<char, vector<ll>> chk;
		LP(i, 0, 5)chk[t[i]].push_back(i);
		if (chk.size() == 4 && chk[t[0]] == vector<ll>({0, 2}))++ans;
	}
	cout << ans;
}