The Fair Nut found a string s. The string consists of lowercase Latin letters. The Nut is a curious guy, so he wants to find the number of strictly increasing sequences p_1, p_2, …, p_k, such that: 

  1. For each i (1 ≤ i ≤ k), s_{p_i} = 'a'. 
  2. For each i (1 ≤ i < k), there is such j that p_i < j < p_{i + 1} and s_j = 'b'. 



The Nut is upset because he doesn't know how to find the number. Help him.

This number should be calculated modulo 10^9 + 7.

Input

The first line contains the string s (1 ≤ |s| ≤ 10^5) consisting of lowercase Latin letters.

Output

In a single line print the answer to the problem — the number of such sequences p_1, p_2, …, p_k modulo 10^9 + 7.

Examples

Input

abbaa


Output

5

Input

baaaa


Output

4

Input

agaa


Output

3

Note

In the first example, there are 5 possible sequences. [1], [4], [5], [1, 4], [1, 5].

In the second example, there are 4 possible sequences. [2], [3], [4], [5].

In the third example, there are 3 possible sequences. [1], [3], [4].
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Scanner;

public final class ThefairNutAndStringCF {
    public static  int max= (int) (Math.pow(10,9)+7);
    public static void main(String[] args) {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            Scanner sc=new Scanner(br);
            String s=sc.next();
            StringBuilder sb=new StringBuilder(s);
            int i=0;
            while (i<sb.length()){
                if(sb.charAt(i)!='a' && sb.charAt(i)!='b'){
                    sb.replace(i,i+1,"");
                }else
                    i++;
            }
            int ii=0;
            ArrayList<Integer> l=new ArrayList<>();
            while (ii<sb.length()){
                while (ii<sb.length() && sb.charAt(ii)!='a'){
                    ii++;
                }
                int count=0;
                while (ii<sb.length() && sb.charAt(ii)=='a'){
                    ii++;
                    count++;
                }
                l.add(count);
            }
            if(l.size()==0){
                System.out.println("0");
            }else if(l.size()==1){
                System.out.println(l.get(0));
            }else{
                long ans=1;
                for(int j=0;j<l.size();j++){
                    ans=((ans)%max*(l.get(j)+1)%max)%max;
                }
                System.out.println(ans-1);
            }
    }
}
