#include <cstdio>
#include <vector>
#include <map>
#include <algorithm>
#include <cmath>
#include <iostream>
#include <string>
#include <set>

#define rep(i,N) for(int (i)=0;(i)<(N);(i)++)
#define MOD 1000000007

using namespace std;

int pow_mod(int a, int b, int p) {
	if (b == 0)return 1;
	else if (b % 2 == 0)return (pow_mod(a*a, b / 2, p) % p);
	else return (pow_mod(a, b - 1, p)*a%p);
}

int factorial_mod(int a, int p) {
	if (!a)return 1;
	else return a * factorial_mod(a - 1, p) % p;
}

int sum_digit(int N) {
	int ans = 0;
	for (; N != 0;) {
		ans += N % 10;
		N /= 10;
	}
	return ans;
}

string s;
int len,cnt=0;

int main(){
	cin >> s;
	len = s.length();
	rep(i, len)if (s[i] == 'c')cnt++;
	printf("%d\n", min(cnt - 1, len - cnt));
	return 0;
}