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.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Stack;
import java.util.TreeSet;
				 
				 
				 
				 
				 
				public class Solution1 implements Runnable
				{
				    static final long MOD = 1000000007;
				    static class InputReader
				    {
				        private InputStream stream;
				        private byte[] buf = new byte[1024];
				        private int curChar;
				        private int numChars;
				        private SpaceCharFilter filter;
				        private BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
				 
				        public InputReader(InputStream stream)
				        {
				            this.stream = stream;
				        }
				        
				        public int read()
				        {
				            if (numChars==-1) 
				                throw new InputMismatchException();
				            
				            if (curChar >= numChars)
				            {
				                curChar = 0;
				                try 
				                {
				                    numChars = stream.read(buf);
				                }
				                catch (IOException e)
				                {
				                    throw new InputMismatchException();
				                }
				                
				                if(numChars <= 0)                
				                    return -1;
				            }
				            return buf[curChar++];
				        }
				     
				        public String nextLine()
				        {
				            String str = "";
				            try
				            {
				                str = br.readLine();
				            }
				            catch (IOException e)
				            {
				                e.printStackTrace();
				            }
				            return str;
				        }
				        public int nextInt()
				        {
				            int c = read();
				            
				            while(isSpaceChar(c)) 
				                c = read();
				            
				            int sgn = 1;
				            
				            if (c == '-') 
				            {
				                sgn = -1;
				                c = read();
				            }
				            
				            int res = 0;
				            do 
				            {
				                if(c<'0'||c>'9') 
				                    throw new InputMismatchException();
				                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 
				            {
				                if (c < '0' || c > '9')
				                    throw new InputMismatchException();
				                res *= 10;
				                res += c - '0';
				                c = read();
				            }
				            while (!isSpaceChar(c));
				                return res * sgn;
				        }
				        
				        public double nextDouble() 
				        {
				            int c = read();
				            while (isSpaceChar(c))
				                c = read();
				            int sgn = 1;
				            if (c == '-') 
				            {
				                sgn = -1;
				                c = read();
				            }
				            double res = 0;
				            while (!isSpaceChar(c) && c != '.') 
				            {
				                if (c == 'e' || c == 'E')
				                    return res * Math.pow(10, nextInt());
				                if (c < '0' || c > '9')
				                    throw new InputMismatchException();
				                res *= 10;
				                res += c - '0';
				                c = read();
				            }
				            if (c == '.') 
				            {
				                c = read();
				                double m = 1;
				                while (!isSpaceChar(c)) 
				                {
				                    if (c == 'e' || c == 'E')
				                        return res * Math.pow(10, nextInt());
				                    if (c < '0' || c > '9')
				                        throw new InputMismatchException();
				                    m /= 10;
				                    res += (c - '0') * m;
				                    c = read();
				                }
				            }
				            return res * sgn;
				        }
				        
				        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 boolean isSpaceChar(int c) 
				        {
				            if (filter != null)
				                return filter.isSpaceChar(c);
				            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
				        }
				     
				        public String next() 
				        {
				            return readString();
				        }
				        
				        public interface SpaceCharFilter 
				        {
				            public boolean isSpaceChar(int ch);
				        }
				    }
				     
				    public static void main(String args[]) throws Exception
				    {
				        new Thread(null, new Solution1(),"Solution",1<<26).start();
				    }   
				    static long gcd(long a, long b) 
				    { 
				      if (b == 0) 
				        return a; 
				      return gcd(b, a % b);  
				    } 
				    static long lcm(long a,long b) {
				    	return (a*b)/gcd(a,b);
				    }
				    ArrayList<Integer> adj[];
				    TreeSet<Integer> tmap[];
				    public void run() 
				    {
				    	InputReader sc = new InputReader(System.in);
						PrintWriter w = new PrintWriter(System.out);
						String s = sc.next();
						long[] dp = new long[s.length()];
						long[] ind = new long[s.length()];
						int last = -1;
						for(int i = 0;i < s.length();i++) {
							if(s.charAt(i) == 'a') {
								ind[i] = last;
							}
							if(s.charAt(i) == 'b') {
								last = i;
							}
						}
						long[] prefix=  new long[s.length()];
						for(int i = 0;i < s.length();i++) {
							if(s.charAt(i) == 'a') {
								if(ind[i] == -1) {
									dp[i] = 1;
								}else {
									dp[i] = (1L + prefix[(int) ind[i]]) % MOD;
								}
							}else {
								dp[i] = 0;
							}
							prefix[i] = (i == 0) ? dp[i] : (prefix[i-1] + dp[i]) % MOD;
						}
						long fans=  0;
						for(int i = 0;i < s.length();i++) {
							fans = (fans + dp[i]) % MOD;
						}
						w.println(fans);
						w.close();
						
				    }
				   
				    static long power(long a,long b,long mod) {
						long ans = 1;
						a = a % mod;
						while(b != 0) {
							if(b % 2 == 1) {
								ans = (ans * a) % mod;
							}
							a = (a * a) % mod;
							b = b/2;
						}
						return ans;
					}
				    static long pow(long a,long b) {
						long ans = 1;
						while(b != 0) {
							if(b % 2 == 1) {
								ans = (ans * a);
								if(ans < 0) {
									return -1;
								}
							}
							a = (a * a);
							if(a < 0) {
								return -1;
							}
							b = b/2;
						}
						return ans;
					}
				    long[] fact = new long[100005];
				   void pre() {
					   fact[0] = 1;
					   for(int i = 1;i < 100005;i++) {
						   fact[i] = (fact[i-1] * i) % MOD;
					   }
				   }
				    class Pair implements Comparable<Pair>{
				        String a;
				        int b;
				        
				        Pair(String a,int b){
				            this.b = b;
				            this.a = a;
				            
				        }
				        public boolean equals(Object o) {
				            Pair p = (Pair)o;
				            return this.a == p.a && this.b == this.b;
				        }
				        public int hashCode(){
				            return a.hashCode()*27 + Long.hashCode(b)*31;
				        }
				        public int compareTo(Pair p) {
				        	return Long.compare(this.b,p.b);
				        }
				    }
				    
				}