#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>
#include<list>
#include<bitset>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000

using namespace std;


int main(void) {
	string s;
	int total = 1000;

	cin >> s;

	FOR(i, 0, s.size() - 1) {
		if (s[i] == 'c') {
			FOR(t, i + 1, s.size() - 1) {
				if (s[t] == 'w') {
					FOR(u, t + 1, s.size() - 1) {
						if (s[u] == 'w') {
							if (total > u - i+1) {
								total = u - i+1;
							}
						}
					}
				}
			}
		}
	}
	if (total == 1000) {
		cout << -1 << endl;
	}
	else {
		cout << total << endl;
	}
	return 0;
}