#include<stdio.h>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>
#include <stdio.h>

using namespace std;

int main() {

	string S;
	cin >> S;

	int ans = 0, cnt = 0, sta = 0;

	for (int i = 0; i < S.size(); i++) {
		//cout << "i: " << i << " cnt: " << cnt <<" sta: "<<sta<< endl;
		if (sta == 1 || sta == 2) cnt++;
		if (sta == 0 && S[i] == 'c') {
			sta = 1;
		}else if (sta == 1 && S[i] == 'w') {
			sta = 2;
		}else if (sta == 2 && S[i] == 'w') {
			sta = 0;
			ans = max(ans, cnt + 1);
			cnt = 0;
		}else if ((sta == 1 || sta == 2) && S[i] == 'c') {
			sta = 0;
			cnt = 0;
		}
	}

	if (ans == 0) cout << -1 << endl;
	else cout << ans << endl;

	return 0;
}