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

int main() {
	string S;
	cin >> S;
	int ans = 10000;
	for( int i = 0; i < S.length(); i++ ) {
		if( S[i] == 'c' ) {
			bool flag = false;
			for( int j = i + 1; j < S.length(); j++ ) {
				if( S[j] == 'w' ) {
					if( flag ) {
						ans = min( j - i + 1, ans );
					}
					flag = true;
				}
			}
		}
	}
	cout << (ans == 10000 ? -1 : ans) << endl;
}