import java.util.Scanner;
// 偶串
public class EvenString {

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		String str = input.nextLine();
		int len = str.length();
		int result = 0;
		for(int i = 2;i<len;i+=2){
			String substr = str.substring(0, len-i);
			if(isEvenString(substr)){
				result = substr.length();
				break;
			}
		}
		System.out.println(result);
	}
	
	public static boolean isEvenString(String str){
		int len = str.length();
		if(len%2==0){
			int i=0,j=len/2;
			for(;i<len/2;i++){
				if(str.charAt(i) == str.charAt(j)){
					j++;
				}else{
					return false;
				}
			}
		}else{
			return false;
		}
		return true;
	}
}