#include <iostream> #include <vector> using namespace std; int main() { string s; cin>>s; int n = s.length(); vector<vector<int>> dp(n , vector<int>(n)); for(int g=0; g<n; g++){ int i =0; int j=i+g; while( i < n && j < n){ if(g == 0){ dp[i][j] = 1; }else if(g == 1){ if(s[i] == s[j]){ dp[i][j] = 2; } else{ dp[i][j] = 3; } }else{ dp[i][j] = dp[i][j-1] + dp[i+1][j] - dp[i+1][j-1] + 1; } i++; j = i+g; } } cout<<dp[0][n-1]; }