    import java.util.Scanner;
     
    public class Main {
     
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	}
    } import java.util.Scanner; Scanner java.util public class Main {
     
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	}
    } Main public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	} main {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char A[] = new char[200000]; A new char[200000] 200000 A = sc.next().toCharArray() A sc.next().toCharArray() sc.next().toCharArray sc.next() sc.next sc int max=1; max 1 int count=0; count 0 boolean flag=false; flag false for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		} int i=0; int i=0; i 0 i<A.length i A.length A A.length i++ i++ i {
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		} {
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		} if(A[i]=='A'){
    				flag=true;
    			} A[i]=='A' A[i] A i 'A' {
    				flag=true;
    			} flag=true flag true if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			} A[i]=='Z' && flag A[i]=='Z' A[i] A i 'Z' flag {
    				count++;
    				if(max<count)
    				max=count;
    			} count++ count if(max<count)
    				max=count; max<count max count max=count max count if(flag){
    				count++;
    			} flag {
    				count++;
    			} count++ count System.out.println(max) System.out.println System.out System System.out max String[] args args public class Main {
     
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	}
    } public class Main {
     
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	}
    } Main
    import java.util.Scanner;
     
    public class Main {
     
    	public static void main(String[] args) {
    		// TODO Auto-generated method stub
    		Scanner sc = new Scanner(System.in);
    		char A[] = new char[200000];
    		A = sc.next().toCharArray();
    		int max=1;
    		int count=0;
    		boolean flag=false;
    		for(int i=0;i<A.length;i++){
    			if(A[i]=='A'){
    				flag=true;
    			}
    			if(A[i]=='Z' && flag){
    				count++;
    				if(max<count)
    				max=count;
    			}
    			else if(flag){
    				count++;
    			}
    		}
    		System.out.println(max);
    	}
    }