String Receiver

## Checks for aa+b*


## Code for String_rec.java
import java.util.*;
//aa+b*
public class String_rec {

	String str;
	int state=0;
	void StrCheck(){
		if(str.charAt(0) == 'a'){
			state=1;
			if((str.length()==2) && (str.charAt(1) == 'a')){
				state=2;
			}
			else{
				state=-1;
			}
		}
		else if(str.charAt(0) == 'b'){
			state=3;
			for(int i=1;i<str.length();i++){
				if(str.charAt(i) != 'b'){
					state=-1;
				}
			}
		}
		if((state == 2) || (state == 3)){
			System.out.println("string is accepted");
		}
		else{
			System.out.println("string is rejected");
		}
	}
	
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		String_rec obj=new String_rec();
		
		obj.str=sc.next();
		obj.StrCheck();
	}
}


## Output
$ java String_rec
aa
string is accepted