#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin
#include <ios>			//fixed
#include <iomanip>		//setprecision
#include <sstream>		//stringstream

using namespace std;

int main() {

	string S;
	cin >> S;

	if (S.length() < 3) {
		cout << -1 << endl;
		return 0;
	}

	int min = INT_MAX;


	for (unsigned int i = 0; i < S.length() - 2; i++) {
		if (S[i] == 'c') {
			for (unsigned int j = i + 1; j < S.length() - 1; j++) {
				if (S[j] == 'w') {
					for (unsigned int k = j + 1; k < S.length(); k++) {
						if (S[k] == 'w') {
							int temp = k - i + 1;
							if (min > temp) {
								min = temp;
							}
							break;
						}
					}
					break;
				}
			}
		}
	}

	if (min == INT_MAX) {
		cout << -1 << endl;
	}
	else {
		cout << min << endl;
	}

	return 0;

}