#include<iostream>
#include<cstdio>
#include<string>
using namespace std;

int main() {
	string str;
	cin >> str;

	int minLength = 102;
	for (auto i = str.begin(); i != str.end() ; i++)
	{
		if (*i=='c')
		{
			int count = 0, length = 1;
			for (auto j = i + 1; j != str.end() ; j++)
			{
				length++;
				if (*j == 'w') count++;
				if (count == 2)
				{
					if (minLength > length)	minLength = length;
					break;
				}
			}
		}
	}
	if (minLength == 102) minLength = -1;
	cout << minLength << endl;

	return 0;
}