#include using namespace std; #define DEBUG(x) cerr<<#x<<": "< #define vl vector #define vii vector< vector > #define vll vector< vector > #define vs vector #define pii pair #define pis pair #define psi pair #define pll pair template pair operator+(const pair &s, const pair &t) { return pair(s.first + t.first, s.second + t.second); } template pair operator-(const pair &s, const pair &t) { return pair(s.first - t.first, s.second - t.second); } template ostream& operator<<(ostream& os, pair p) { os << "(" << p.first << ", " << p.second << ")"; return os; } #define X first #define Y second #define rep(i,n) for(int i=0;i<(int)(n);i++) #define rep1(i,n) for(int i=1;i<=(int)(n);i++) #define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--) #define rrep1(i,n) for(int i=(int)(n);i>0;i--) #define REP(i,a,b) for(int i=a;i bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; } #define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end()); const ll inf = 1000000001; const ll INF = (ll)1e18 + 1; const long double pi = 3.1415926535897932384626433832795028841971L; #define Sp(p) cout<> s; int n = s.size(); vl pre(26); ll p = 1; ll ans = 0; vl power2(n + 1); power2[0] = 1; rep (i, n) power2[i + 1] = power2[i] * 2 % MOD; rep (i, n) { ll zen = p; zen -= pre[s[i] - 'a']; ans += zen * power2[n - 1 - i] % MOD; pre[s[i] - 'a'] += power2[i]; pre[s[i] - 'a'] %= MOD; p *= 2; p %= MOD; } cout << (ans % MOD + MOD) % MOD << endl; }