#include <bits/stdc++.h>
using namespace std;
const int K = 26;
const int md = 1e9 + 7;
int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(nullptr);
	string S;
	cin >> S;
	vector<pair<int,int>> dp(K);
	for(char ch: S) {
		auto[sum, cnt] = dp[ch - 'a'];
		sum += sum;
		cnt += cnt;
		sum %= md, cnt %= md;
		for(int j = 0; j < 26; j++) if(ch - 'a' != j) {
			cnt += dp[j].second;
			sum += (dp[j].first + dp[j].second) % md;
			cnt %= md, sum %= md;
		}
		sum += 1, cnt += 1;
		dp[ch - 'a'] = {sum % md, cnt % md};
	}
	int ans = 0;
	for(int i = 0; i < 26; i++) {
		ans += dp[i].first;
		ans %= md;
	}
	cout << ans << "\n";
}