#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
  string S;
  cin>>S;
  int a = 0,b=0;
  for(int i=0;i<S.size();i++){
    if(S[i] == 'c') a++;
    else b++;
  }
  cout<<max(0ll,min(a-1,b))<<endl;
}