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



string s;
//-----------------------------------------------------------------
int main() {
	cin >> s;

	int a = 0, b = 0;
	rep(i, 0, s.length()) {
		if (s[i] == 'c')
			a++;
		else
			b++;
	}

	int ans = min(a - 1, b);
	if (ans < 0) ans = 0;
	cout << ans << endl;
}