#include <fstream>
#include <string.h>
using namespace std;
ifstream fi("pscpld.in");
ofstream fo("pscpld.out");
char A[1000001];
char X[2000005];
int n,i;
int P[2000005];
int id,mx;
long long rez;
int main()
{
    fi>>A;
    X[0]='$';
    X[1]='#';
    n=2;
    for (i=0;A[i]!='\0';i++)
    {
        X[n++]=A[i];
        X[n++]='#';
    }
    X[n]='\0';
    P[0]=1;
    P[1]=1;
    id=1;
    mx=1;
    for (i=2;i<n;i++)
    {
        P[i]= mx > i ? min(P[2*id-i], mx-i) : 1;
        while (X[i + P[i]] == X[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+=(P[i]/2);
    fo<<rez<<'\n';
    fi.close();
    fo.close();
    return 0;
}