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

const int mod = 1000000007;
long long dp[200005][30];
long long dp2[30];

inline long long modpow(long long a,long long b,long long m) {
    long long ans = 1;
    while(b) {
        if(b & 1) {
            (ans *= a) %= m;
        }
        (a *= a) %= m;
        b /= 2;
    }
    return ans;
}

int main() {
    string S;
    cin >> S;
    for(int i = 0; i < S.size(); i++) {
        int c = S[i]-'a';
        dp[i+1][c]++;
        dp[i+1][c] %= mod;
        dp2[c] += modpow(2,i,mod);
        dp2[c] %= mod;
        for(int j = 0; j < 26; j++) {
            dp[i+1][j] += dp[i][j];
            dp[i+1][j] %= mod;
            if(j == c) {
                dp[i+1][j] += dp[i][j];
                dp[i+1][j] %= mod;
            }
            else {
                dp[i+1][c] += dp[i][j];
                dp[i+1][c] %= mod;
                dp[i+1][c] += dp2[j];
                dp[i+1][c] %= mod;
            }
        }
    }
    long long ans = 0;
    for(int i = 0; i < 26; i++) {
        ans += dp[S.size()][i];
        ans %= mod;
    }
    cout << ans << endl;
}