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

int main(void) {
	string s;
	cin >> s;
	bool flag = 0;
	int count = 0;
	int now,ans=5000000,tmp=-1;
	int j=0;
	for (int i = 0; i < s.length(); ++i) {
		count=0;
		if (s[i] == 'c') {
			now=i;
			j=i;
			while (j < s.length()) {
				j++;
				if(s[j]=='w'&&count==0){
					count++;
				}else if(s[j]=='w'&&count==1){
					tmp=j-now+1;
					ans=min(ans,tmp);
				}
			}
		}
	}
	cout<<((ans!=5000000)?ans:-1)<<endl;
}