#include using namespace std; #pragma region Template // Define using ll = long long; using ull = unsigned long long; using ld = long double; template using pvector = vector>; template using rpriority_queue = priority_queue, greater>; constexpr const ll dx[4] = {1, 0, -1, 0}; constexpr const ll dy[4] = {0, 1, 0, -1}; constexpr const ll MOD = 1e9 + 7; constexpr const ll mod = 998244353; constexpr const ll INF = 1LL << 60; constexpr const ll inf = 1 << 30; constexpr const char rt = '\n'; constexpr const char sp = ' '; #define rt(i, n) (i == (ll)(n) -1 ? rt : sp) #define len(x) ((ll)(x).size()) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define mp make_pair #define mt make_tuple #define pb push_back #define eb emplace_back #define ifn(x) if (not(x)) #define elif else if #define elifn else ifn #define fi first #define se second #define uniq(x) (sort(all(x)), (x).erase(unique(all(x)), (x).end())) using graph = vector>; template using wgraph = vector>; bool __DIRECTED__ = true; bool __ZERO_INDEXED__ = false; istream &operator>>(istream &is, graph &g) { ll a, b; is >> a >> b; if (__ZERO_INDEXED__ == false) a--, b--; g[a].pb(b); if (__DIRECTED__ == false) g[b].pb(a); return is; } template istream &operator>>(istream &is, wgraph &g) { ll a, b; T c; is >> a >> b >> c; if (__ZERO_INDEXED__ == false) a--, b--; g[a].pb({b, c}); if (__DIRECTED__ == false) g[b].pb({a, c}); return is; } template bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; } // Debug #define debug(...) \ { \ cerr << __LINE__ << ": " << #__VA_ARGS__ << " = "; \ for (auto &&__i : {__VA_ARGS__}) cerr << "[" << __i << "] "; \ cerr << rt; \ } #define dump(a, h, w) \ { \ cerr << __LINE__ << ": " << #a << " = [" << rt; \ rep(__i, h) { \ rep(__j, w) { \ if (abs(a[__i][__j]) >= INF / 2 and a[__i][__j] <= -INF / 2) cerr << '-'; \ if (abs(a[__i][__j]) >= INF / 2) cerr << "∞" << sp; \ else \ cerr << a[__i][__j] << sp; \ } \ cerr << rt; \ } \ cerr << "]" << rt; \ } #define vdump(a, n) \ { \ cerr << __LINE__ << ": " << #a << " = ["; \ rep(__i, n) { \ if (__i) cerr << sp; \ if (abs(a[__i]) >= INF / 2 and a[__i] <= -INF / 2) cerr << '-'; \ if (abs(a[__i]) >= INF / 2) cerr << "∞" << sp; \ else \ cerr << a[__i]; \ } \ cerr << "]" << rt; \ } // Loop #define inc(i, a, n) for (ll i = (a), _##i = (n); i <= _##i; ++i) #define dec(i, a, n) for (ll i = (a), _##i = (n); i >= _##i; --i) #define rep(i, n) for (ll i = 0, _##i = (n); i < _##i; ++i) #define each(i, a) for (auto &&i : a) // Stream #define fout(n) cout << fixed << setprecision(n) struct io { io() { cin.tie(nullptr), ios::sync_with_stdio(false); } } io; ///* // Speed #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wunknown-pragmas" #pragma GCC optimize("Ofast,unroll-loops") #pragma GCC target( \ "sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native,arch=skylake-avx512") #pragma GCC diagnostic pop //*/ // Math inline constexpr ll gcd(const ll a, const ll b) { return b ? gcd(b, a % b) : a; } inline constexpr ll lcm(const ll a, const ll b) { return a / gcd(a, b) * b; } inline constexpr ll modulo(const ll n, const ll m = MOD) { ll k = n % m; return k + m * (k < 0); } inline constexpr ll chmod(ll &n, const ll m = MOD) { n %= m; return n += m * (n < 0); } inline constexpr ll mpow(ll a, ll n, const ll m = MOD) { ll r = 1; rep(i, 64) { if (n & (1LL << i)) r *= a; chmod(r, m); a *= a; chmod(a, m); } return r; } inline ll inv(const ll n, const ll m = MOD) { ll a = n, b = m, x = 1, y = 0; while (b) { ll t = a / b; a -= t * b; swap(a, b); x -= t * y; swap(x, y); } return modulo(x, m); } #pragma endregion const ll mo = 1e9 + 7; struct mint { ll x; mint(ll x = 0) : x((x % mo + mo) % mo) {} mint operator-() const { return mint(-x); } mint &operator+=(const mint &a) { if ((x += a.x) >= mo) x -= mo; return *this; } mint &operator-=(const mint &a) { if ((x += mo - a.x) >= mo) x -= mo; return *this; } mint &operator*=(const mint &a) { (x *= a.x) %= mo; 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; } bool operator==(const mint &a) const { return x == a.x; } bool operator!=(const mint &a) const { return x != a.x; } bool operator<=(const mint &a) { return x <= a.x; } bool operator<(const mint &a) { return x < a.x; } friend ll abs(const mint &a) { return a.x; } friend mint pow(const mint &a, ll n) { if (!n) return 1; mint b = pow(a, n >> 1); b *= b; if (n & 1) b *= a; return b; } mint inv() const { return pow(*this, mo - 2); } mint &operator/=(mint a) { return (*this) *= a.inv(); } mint operator/(mint a) const { return mint(*this) /= a; } friend istream &operator>>(istream &is, mint &a) { ll t; is >> t; a = mint(t); return is; } friend ostream &operator<<(ostream &os, mint a) { os << a.x; return os; } }; mint operator""_M(const ull n) { return mint(n); } signed main() { string S; cin >> S; ll N = len(S); mint res = 0; rep(c, 26) { mint cnt = 0; rep(i, N) { if (S[i] == 'a' + c) { res += (pow(2_M, i) - cnt) * pow(2_M, N - 1 - i); cnt += pow(2_M, i); } } } cout << res << rt; }