#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

constexpr int P = 1000000007;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

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

    ll p[26] = {}, q[26] = {};
    for (int i = 0; i < n; i++) {
        int x = s[i] - 'a';

        ll t = 0;
        for (int c = 0; c < 26; c++) {
            t += q[c] + (c != x) * p[c];
        }
        q[x] += t;
        q[x]++;
        q[x] %= P;

        t = 0;
        for (int c = 0; c < 26; c++) {
            t += p[c];
        }
        p[x] += t;
        p[x]++;
        p[x] %= P;
    }

    ll r = 0;
    for (int c = 0; c < 26; c++) {
        r += q[c];
    }

    cout << r % P << endl;

    return 0;
}