#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)

int main(){
	string s; cin>>s;
	int sk=s.length();
	int c=0;
	rep(i,sk) if(s[i]=='c') c++;
	int w=sk-c;
	if(c==w) cout << w-1 << endl;
	else if(c>w) cout << w << endl;
	else cout << c-1 << endl;
}