import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	} main {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1) System.out.println System.out System System.out a.lastIndexOf("Z") - a.indexOf("A") + 1 a.lastIndexOf("Z") - a.indexOf("A") a.lastIndexOf("Z") a.lastIndexOf a "Z" a.indexOf("A") a.indexOf a "A" 1 sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	}
} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String a = sc.next();
		System.out.println(a.lastIndexOf("Z") - a.indexOf("A") + 1);
		sc.close();
	}
}