#define _USE_MATH_DEFINES #include <iostream> #include <iomanip> #include <algorithm> #include <cmath> #include <string> #include <list> #include <queue> #include <vector> #include <complex> ///////// #define REP(i, x, n) for(int i = x; i < n; i++) #define rep(i,n) REP(i,0,n) #define P(p) std::cout<<(p)<<std::endl; ///////// typedef long long LL; typedef long double LD; ///////// using namespace::std; ///////// int n=0; string s[1024]; string str; int solve(int top,int end,string ss){ if(end<top){ rep(i,n){ if(s[i]==ss){ return 0; } } s[n]=ss; ++n; return 1; } ////// int ans = 0; { ans += solve(top+1,end,ss + str[top]); ans += solve(top,end-1,ss + str[end]); } return ans; } int main(void){ std::cin.tie(0); std::ios::sync_with_stdio(false); std::cout << std::fixed;// //cout << setprecision(6);// cin>>str; int ans; ans = solve(0,str.size()-1,""); P(ans); return 0; }