//ループ愚直全探索は☆1ですかね…
#include <iostream>
#include <string>
using namespace std;

int main(){
	string s;
	int ans = 364;
	
	cin >> s;
	for( int l = 0; l < s.length(); l++ ){
		for( int r = l; r < s.length(); r++ ){
			char *search = "cww ";
			int cor = 0;
			for( int i = l; i <= r; i++ ){
				if( s[i] == search[cor] ){
					cor++;
				}
			}
			if( cor == 3 ){
				ans = min(r - l + 1, ans);
			}
		}
	}
	if( ans == 364 )
		cout << -1 << endl;
	else
		cout << ans << endl;
	return 0;
}