#include using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- ll dp[202020][27]; const ll mo=1000000007; string S; ll p2[202020]; void solve() { int i,j,k,l,r,x,y; string s; dp[0][26]=1; p2[0]=1; FOR(i,201010) p2[i+1]=p2[i]*2%mo; ll ret=0; cin>>S; FOR(i,S.size()) { FOR(j,27) { // keep (dp[i+1][j]+=dp[i][j])%=mo; // add (dp[i+1][S[i]-'a']+=dp[i][j])%=mo; if(j!=S[i]-'a' && j!=26) { (ret+=dp[i][j]*p2[S.size()-1-i])%=mo; } } } FOR(i,26) ret+=dp[S.size()][i]; cout<