package
yanzhengma;
import
java.math.*;
import
java.util.Random;
import
java.util.Scanner;
public
class
RandomStr {
public
static
void
main(String[] args) {
Scanner sc =
new
Scanner(System.in);
String str=
"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
;
StringBuilder sb=
new
StringBuilder(
4
);
for
(
int
i=
0
;i<
4
;i++)
{
char
ch=str.charAt(
new
Random().nextInt(str.length()));
sb.append(ch);
System.out.println(sb.toString());
String m=sc.nextLine();
if
(m==sb.toString())
break
;
}
}
}