#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

inline int power(int a, int b, int mod=M) {
    int x = 1;
    a %= mod;
    while (b) {
        if (b & 1) x = (x * a) % mod; 
        a = (a * a) % mod;
        b >>= 1;
    }
    return x;
}


//_ ***************************** START Below *******************************




string a;

int consistency(int n){
	
    vector<vector<int>> dp(n, vector<int>(n, 0));
    
    
    for(int gap=0; gap<n; gap++){
        for(int i=0, j=gap; j<n; i++, j++){
            if(gap == 0){
                dp[i][j] = 1;
            }
            else if(gap == 1){
                if(a[i] == a[j]) dp[i][j] = 3;
                else dp[i][j] = 2;
            }
            else{
                if(a[i] == a[j]){
                    dp[i][j] = dp[i][j-1] + dp[i+1][j] + 1;
                }
                else{
                    dp[i][j] = dp[i][j-1] + dp[i+1][j] - dp[i+1][j-1];
                }
            }
        }
    }
    
    return dp[0][n-1];

}















int practice(int n){


    return 0;
}





void solve() {
    
    
    cin >> a;;
    
    int n = a.size();
    
    cout << consistency(n) << endl;


}





int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}