#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for(int i=0; i<int(n); ++i)
const int MOD  = int(1e9)+7;


struct mint {
  ll x;
  mint(ll x=0) : x((x%MOD+MOD)%MOD) {}
  mint operator-() const { return mint(-x);}
  mint& operator+=(const mint a) { if ((x += a.x) >= MOD) x -= MOD; return *this; }
  mint& operator-=(const mint a) { if ((x -= a.x) < 0) x += MOD; return *this; }
  mint& operator*=(const mint a) { (x *= a.x) %= MOD; return *this; }
  mint operator+(const mint a) const { return mint(*this) += a; }
  mint operator-(const mint a) const { return mint(*this) -= a; }
  mint operator*(const mint a) const { return mint(*this) *= a; }
};
ostream& operator<<(ostream& os, const mint& a) { return os << a.x; }
using Vm = vector<mint>;


int main() {
  const int M = 26;
  string s; cin >> s;
  int n = s.size();

  Vm pw(n+1);
  pw[0] = 1;
  rep(i, n) pw[i+1] = pw[i] + pw[i];

  Vm dp(M+1);
  dp[M] = 1;

  mint ans = pw[n] - 1;
  rep(i, n) {
    Vm _dp = dp;
    int x = s[i] - 'a';
    rep(j, M+1) {
      _dp[x] += dp[j];
      if (x != j && j < M) ans += dp[j] * pw[n-1-i];
    }
    swap(dp, _dp);
  }
  cout << ans << "\n";
  return 0;
}