#include <bits/stdc++.h>
using namespace std;

#define int ll
using ll = long long;

const int MOD = 1e9 + 7;

int32_t main() {
    cin.tie(0)->sync_with_stdio(0);

    string s;
    cin >> s;
    int n = s.size();

    vector<int> cnt(26), dp(26);
    int tot = 0, pot = 1;
    for (int i = 0; i < n; i++) {
        int ans = tot + 1;
        for (int j = 0; j < 26; j++) {
            if (s[i] - 'a' != j) ans = (ans + cnt[j]) % MOD;
        }
        dp[s[i] - 'a'] = (dp[s[i] - 'a'] + ans) % MOD;
        cnt[s[i] - 'a'] = (cnt[s[i] - 'a'] + pot) % MOD;
        pot = pot*2 % MOD;
        tot = (tot + ans) % MOD;
    }

    cout << tot << endl;
}