#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include <string>
#include <cstdlib>
#include <stack>
#include <queue>
#include <cmath>

#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define repp(i,j,k) for(int i=j;i>=k;i--)
#define Sort(x) sort(x.begin(),x.end()); 
#define ll long long
int mod=1e9+7;
const int INF = 1e9;

using namespace std;


int main(void) {
	string s;
	cin >> s;
	int minn = INF;
	bool judge = true;
	rep(i, 0, s.length()) {
		if (s[i] == 'c') {
			int w = 0;
			rep(j, i, s.length()) {
				if (s[j] == 'w') {
					if (w == 0)w++;
					else if (w == 1) {
						minn = min(minn, j - i + 1);
						judge = false;
						break;
					}
				}
			}
		}
	}
	if (judge)cout << -1 << endl;
	else cout << minn << endl;

	return 0;
}