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.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution 
{
	static class InputReader
	{
	    private final InputStream stream;
	    private final byte[] buf = new byte[8192];
	    private int curChar, snumChars;

	    public InputReader(InputStream st) {
	      this.stream = st;
	    }

	    public int read() {
	      if (snumChars == -1)
	        throw new InputMismatchException();
	      if (curChar >= snumChars) {
	        curChar = 0;
	        try {
	          snumChars = stream.read(buf);
	        } catch (IOException e) {
	          throw new InputMismatchException();
	        }
	        if (snumChars <= 0)
	          return -1;
	      }
	      return buf[curChar++];
	    }

	    public int nextInt() {
	      int c = read();
	      while (isSpaceChar(c)) {
	        c = read();
	      }
	      int sgn = 1;
	      if (c == '-') {
	        sgn = -1;
	        c = read();
	      }
	      int res = 0;
	      do {
	        res *= 10;
	        res += c - '0';
	        c = read();
	      } while (!isSpaceChar(c));
	      return res * sgn;
	    }

	    public long nextLong() {
	      int c = read();
	      while (isSpaceChar(c)) {
	        c = read();
	      }
	      int sgn = 1;
	      if (c == '-') {
	        sgn = -1;
	        c = read();
	      }
	      long res = 0;
	      do {
	        res *= 10;
	        res += c - '0';
	        c = read();
	      } while (!isSpaceChar(c));
	      return res * sgn;
	    }

	    public int[] nextIntArray(int n) {
	      int a[] = new int[n];
	      for (int i = 0; i < n; i++) {
	        a[i] = nextInt();
	      }
	      return a;
	    }

	    public String readString() {
	      int c = read();
	      while (isSpaceChar(c)) {
	        c = read();
	      }
	      StringBuilder res = new StringBuilder();
	      do {
	        res.appendCodePoint(c);
	        c = read();
	      } while (!isSpaceChar(c));
	      return res.toString();
	    }

	    public String nextLine() {
	      int c = read();
	      while (isSpaceChar(c))
	        c = read();
	      StringBuilder res = new StringBuilder();
	      do {
	        res.appendCodePoint(c);
	        c = read();
	      } while (!isEndOfLine(c));
	      return res.toString();
	    }

	    public boolean isSpaceChar(int c) {
	      return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	    }

	    private boolean isEndOfLine(int c) {
	      return c == '\n' || c == '\r' || c == -1;
	    }
	}
 	public static void main(String[] args) throws Exception
    {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = br.readLine().trim();
        StringBuilder b = new StringBuilder();
        for(int i=0;i<str.length();i++)
        {
            if(str.charAt(i) == 'a' || str.charAt(i) == 'b')
                b.append(Character.toString(str.charAt(i)));
        }
        int i = 0;
        ArrayList<Integer> brr = new ArrayList<>();
        while(i < b.length())
        {
            if(b.charAt(i) == 'a')
            {
                int count = 0;
                while(i < b.length() && b.charAt(i) == 'a')
                {
                    count++;i++;
                }
                brr.add(count);
            }
            else if(b.charAt(i) == 'b')
            {
                while(i < b.length() && b.charAt(i) == 'b')
                    i++;
            }
        }
        long ans = 0;
        long mod = 1000000007;
        for(i=0;i<brr.size();i++)
        {
            //System.out.println(brr.get(i));
            ans = (brr.get(i) + (ans)*(1+brr.get(i)))%mod;
        }
        System.out.println(ans);
    } 
    
}
