#include<iostream>
#include<string>
#include<cstring>
#include<complex>
#include<vector>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<iomanip>
using namespace std;

#define REP(i, j) for (int i = 0; i < (int)j; ++i)
#define FOR(i, j, k) for (int i = (int)j; i < (int)k; ++i)
#define SORT(v) sort(v.begin(), v.end())
#define REVERSE(v) reverse(v.begin(), v.end())
typedef complex<double> P;
typedef vector<int> VI;
typedef long long LL;
typedef pair<int,int> PII;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	string s;
	cin >> s;

	int w1i = -1;
	REP(i,s.length()) {
		if (s[i] == 'w') {
			w1i = i;
			break;
		}
	}
	int ci = -1;
	for (int i = w1i-1; i >= 0; i--) {
		if (s[i] == 'c') {
			ci = i;
			break;
		}
	}
	int w2i = -1;
	FOR(i,w1i+1,s.length()) {
		if (s[i] == 'w') {
			w2i = i;
			break;
		}
	}

	if (ci == -1 || w1i == -1 || w2i == -1) cout << -1 << endl;
	else cout << (w2i - ci + 1) << endl;

	return 0;
}