import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        ArrayList<HashMap<Integer, Integer>> counts = new ArrayList<>();
        HashMap<Integer, Integer> total = new HashMap<>();
        for (int i = 0; i < 26; i++) {
            counts.add(new HashMap<>());
        }
        for (char c : sc.next().toCharArray()) {
            int idx = c - 'a';
            for (int x : counts.get(idx).keySet()) {
                total.put(x, (total.get(x) - counts.get(idx).get(x) + MOD) % MOD);
                counts.get(idx).put(x, counts.get(idx).get(x) * 2 % MOD);
            }
            counts.get(idx).put(1, counts.get(idx).getOrDefault(1, 0) + 1);
            for (int x : total.keySet()) {
                counts.get(idx).put(x + 1, (counts.get(idx).getOrDefault(x + 1, 0) + total.get(x)) % MOD);
            }
            for (int x : counts.get(idx).keySet()) {
                total.put(x, total.getOrDefault(x, 0) + counts.get(idx).get(x));
            }
        }
        long ans = 0;
        for (Map.Entry<Integer, Integer> entry : total.entrySet()) {
            ans += (long)(entry.getKey().intValue()) * entry.getValue() % MOD;
            ans %= MOD;
        }
        System.out.println(ans);
    }
}