#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <sstream>
#include <algorithm>
#include <stack>
#include <vector>
#include <queue>
#include <map>
#include <set>
#include <deque>
#include <functional>
#define _USE_MATH_DEFINES
#include <math.h>
#include <complex>

//#include <atcoder/all>
//using namespace atcoder;

using namespace std;

#define REP(i,n) for(int i = 0; i < (int)n; i++)
#define RREP(i,n) for(int i = (int)n-1; i >= 0; i--)
#define LREP(i,n) for(LL i = 0; i < (LL)n; i++)

#define Vi vector<int>
#define Vl vector<long long>
#define LP pair<long long ,long long>
#define P pair<int, int>
#define T3 tuple<LL, LL, LL>
#define T4 tuple<LL, LL, LL, LL>
#define INF 1000000007
#define SIZE	3010
#define MOD 998244353
typedef long long LL;

int N;
string S;

int main() {
	cin >> S;
	N = S.size();
	int ans = INF;
	REP(i, N) {
		if (S[i] != 'w') continue;
		int l = -INF, r = INF;
		for (int j = i - 1; j >= 0; j--) {
			if (S[j] == 'c') {
				l = j;
				break;
			}
		}
		for (int j = i + 1; j < N; j++) {
			if (S[j] == 'w') {
				r = j;
				break;
			}
		}
		ans = min(ans, r - l + 1);
	}
	if (ans > N) ans = -1;
	cout << ans << endl;
}