//偶串
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String in = scanner.nextLine();
for(int i = 2 ; i < in.length() ; i+=2){
int it = in.length() - i;
String st1 = in.substring(0, it / 2);
String st2 = in.substring(it / 2, it);
if(st1.equals(st2)){
System.out.println(it);
return;
}
}
}
}
//回文
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Map<Character, Integer> inMap = new HashMap<Character, Integer>();
Scanner scanner = new Scanner(System.in);
char[] in = scanner.nextLine().toCharArray();
for(char ct : in){
Integer tmp = inMap.get(ct);
if(tmp == null){
inMap.put(ct, 1);
}else{
inMap.put(ct, tmp + 1);
}
}
int out = 0;
Iterator it = inMap.keySet().iterator();
while(it.hasNext()){
if(inMap.get(it.next()) % 2 == 1){
out++;
}
}
System.out.println(out == 0 ? 1 : out);
}
}