#define _USE_MATH_DEFINES
#include<bits/stdc++.h>
using namespace std;

#define int long long

string S;

int FindCWW(int p)
{
	int cnt = 0;
	for (int i = 0; i < 2; i++)
	{
		while (p < S.size() && S[p] != 'w') cnt++, p++;
		if (p >= S.size()) return 101;
		cnt++; p++;
	}
	return cnt;
}

signed main()
{
	cin >> S;
	int ans = 101;
	for (int i = 0; i < S.size(); i++)
	{
		if (S[i] != 'c') continue;
		ans = min(ans, FindCWW(i));
	}
	if (ans > 100) puts("-1");
	else printf("%lld\n", ans);
	return 0;
}