#include using namespace std; #define ALL(x) x.begin(),x.end() #define rep(i,n) for(int i=0;i<(n);i++) #define debug(v) cout<<#v<<":";for(auto x:v){cout<bool chmax(T &a,const T &b){if(abool chmin(T &a,const T &b){if(b ostream &operator<<(ostream &os,const pair&p){ os< ostream &operator<<(ostream &os,const vector&v){ for(int i=0;i<(int)v.size();i++) os< istream &operator>>(istream &is,pair&p){ is>>p.first>>p.second; return is; } template istream &operator>>(istream &is,vector&v){ for(T &x:v)is>>x; return is; } template struct ModInt{ long long x; ModInt():x(0){} ModInt(long long y):x(y>=0?y%Mod:(Mod-(-y)%Mod)%Mod){} ModInt &operator+=(const ModInt &p){ if((x+=p.x)>=Mod) x-=Mod; return *this; } ModInt &operator-=(const ModInt &p){ if((x+=Mod-p.x)>=Mod)x-=Mod; return *this; } ModInt &operator*=(const ModInt &p){ x=(int)(1ll*x*p.x%Mod); return *this; } ModInt &operator/=(const ModInt &p){ (*this)*=p.inverse(); return *this; } ModInt operator-()const{return ModInt(x);} ModInt operator+(const ModInt &p)const{return ModInt(*this)+=p;} ModInt operator-(const ModInt &p)const{return ModInt(*this)-=p;} ModInt operator*(const ModInt &p)const{return ModInt(*this)*=p;} ModInt operator/(const ModInt &p)const{return ModInt(*this)/=p;} ModInt operator==(const ModInt &p)const{return x==p.x;} ModInt operator!=(const ModInt &p)const{return x!=p.x;} ModInt inverse()const{ int a=x,b=Mod,u=1,v=0,t; while(b>0){ t=a/b; swap(a-=t*b,b);swap(u-=t*v,v); } return ModInt(u); } ModInt pow(long long n)const{ ModInt ret(1),mul(x); while(n>0){ if(n&1) ret*=mul; mul*=mul;n>>=1; } return ret; } friend ostream &operator<<(ostream &os,const ModInt &p){return os<>(istream &is,ModInt &a){long long t;is>>t;a=ModInt(t);return (is);} static int get_mod(){return Mod;} }; using mint=ModInt; template struct comcalc{ vector fact,finv,inv; comcalc():fact(MAX),finv(MAX),inv(MAX){ fact[0]=mint(1),fact[1]=mint(1),finv[0]=mint(1),finv[1]=mint(1),inv[1]=mint(1); for(int i=2;in-r) r=n-r; if(r==0) return 1; mint a=1,b=mint(fact_mod(r)).inverse(); for(int i=0;i; mint dp[200010][26],dpp[200010][26]; signed main(){ string s;cin>>s; int n=(int)s.size(); rep(i,n){ int x=s[i]-'a'; // ε dp[i+1][x]+=1; dpp[i+1][x]+=1; rep(j,26){ dp[i+1][j]+=dp[i][j]; dpp[i+1][j]+=dpp[i][j]; if(j!=x){ dp[i+1][x]+=dp[i][j]+dpp[i][j]; dpp[i+1][x]+=dpp[i][j]; }else{ dp[i+1][x]+=dp[i][j]; dpp[i+1][x]+=dpp[i][j]; } } } mint res=0; rep(i,26)res+=dp[n][i]; // rep(i,n+1){ // cout<