#define _USE_MATH_DEFINES

#include <iostream>	//cin, cout
#include <vector>	//vector
#include <algorithm> //sort,min,max,count
#include <string>	//string
#include <ios>		//fixed
#include <iomanip>	//setprecision
#include <utility> //swap
#include <cstdlib>	//abs(int)
#include <cmath>	//sqrt
#include <sstream>	//stringstream,getline
#include <cmath>	//ceil,M_PI

using namespace std;

int main() {

	string S;
	cin >> S;

	int a = 0, b = 0, c = 0;
	int temp = 0;
	int ans = 101;

	while (1) {
		if (S.find("c", a) != string::npos) {
			a = S.find("c", a) + 1;
			if (S.find("w", a) != string::npos) {
				b = S.find("w", a) + 1;;
				if (S.find("w", b) != string::npos) {
					c = S.find("w", b) + 1;
					temp = c - a + 1;
					if (temp < ans) {
						ans = temp;
					}
				}
			}
		}
		else {
			break;
		}
	}

	if (ans == 101) {
		ans = -1;
	}

	cout << ans << endl;

	return 0;

}