BOJ 1342

#include <iostream>
#include <vector>
using namespace std;

int num[26];
int len;
int ans = 0;
vector<pair<int, int> > v;
void dfs(int depth, int prev) {
	if (depth == len) {
		ans++;
		return;
	}
	for (int i = 0; i < v.size(); i++) {
		if (v[i].second == 0) continue;
		if (v[i].first != prev) {
			v[i].second--;
			dfs(depth + 1, v[i].first);
			v[i].second++;
		}
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	string s;
	cin >> s;
	len = s.length();
	for (int i = 0; i < s.length(); i++) {
		num[s[i] - 'a']++;
	}
	for (int i = 0; i < 26; i++) {
		if (num[i] == 0) continue;
		v.push_back({ i,num[i] });
	}
	dfs(0,-1);
	cout << ans << "\n";
	return 0;
}