getting an error 
cannot find symbol
import java.util.Scanner;
class Abcd
{
public static void main (String args[])
{
char a;
int b;
Scanner x = new Scanner(System.in);
System.out.println("enter a");
a= x.nextChar();
System.out.println("enter b");
b= x.nextInt();
if ((a=='m')&&(b>=21))
{
System.out.println("You are eligible");
}
else
{
if ((a=='f')&&(b>=18))
{
System.out.println("You are eligible");
}
else
{
System.out.println("You are not eligible or you entered wrong gender");
}
}}}