#include<iostream>
#include<string>

using namespace std;

long funct(string s,long n){
    cout<<"lol";
long len=s.size();
long loop = n/len;
long l = n % len;
long rem =0;
long count =0,i;
for(i=0; i<l;i++)
{
    if(s[i] == 'a')
    {
        rem++;
    }
}
while(i<len)
{
    if(s[i] == 'a')
    {
        count++;
        i++;
    }
}
count += rem;
long ans = (loop * count) + rem;
return ans;
}

int main(void) {
    string s;
    cin>>s;
    long ans = funct(s,10);
    cout<<ans<<endl;
    return 0;
}