#include <fstream>
#include <iostream>
using namespace std;
char A[1000001];
char S[2000005];
int  P[2000005];
int n,i;
int id,mx,j,rez;
ifstream fi("pscpld.in");
ofstream fo("pscpld.out");
int main()
{
	fi>>A;
	S[0]='$';
	n=0;
	for (i=0;A[i]!='\0';i++)
	{
		S[++n]='#';
		S[++n]=A[i];
	}
	S[++n]='#';
	S[++n]='\0';
	n--;
	// se va construi sirul P
	P[0]=1;
	id=0;
	mx=0;
	for (i=1;i<=n;i++)
	// se determina P[i]
	{
		if (mx>i)
		{
			j=2*id-i;
			P[i]=min(P[j],mx-i);
		}
		else
			P[i]=1;
		while (S[i + P[i]] == S[i - P[i]])
			P[i]++;
		if (i+P[i]>mx)
		{
			mx=i+P[i];
			id=i;
		}
	}
	rez=0;
	for (i=1;i<=n;i++)
			rez=rez+P[i]/2;
	fo<<rez;
	fi.close();
	fo.close();
	return 0;
}