#include <bits/stdc++.h>

#define NMAX 1000005
using namespace std;

string s, s2;
int v[2 * NMAX];

int main(){
  ios::sync_with_stdio(false);
 	freopen("pscpld.in", "r", stdin);
 	freopen("pscpld.out", "w", stdout);
 	
  cin >> s;

  s2 += '#';
  for(auto it: s)
  		{
  			s2 += it;
  			s2 += '#';
  		}

  v[0] = 1;
  int c = 0, r = 0;
  long long rez = 0;
  for(int i = 1; i < s2.size(); ++i){
  		int lg = 0;
  		if(i <= r)
  			lg = min(v[2 * c - i], r - i + 1);
  		while(i - lg >= 0 && i + lg < s2.size() && s2[i - lg] == s2[i + lg])
  			++lg;
  		v[i] = lg;
  		if(i + lg - 1 > r){
  			r = i + lg - 1;
  			c = i;
  		}

  		if(i % 2 == 0)
  			rez += lg / 2;
  		else rez += (lg + 1) / 2;
  }
  cout << rez << '\n';
  return 0;
}