#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<map>
#include<utility>
#include<set>
#include<stack>
#include<queue>
#include<deque>
#include<cmath>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<bitset>
#include<sstream>
#include<list>
using namespace std;
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define nrep(i,i0,n) for(int i=(i0);i<(int)(n);++i)
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii;
typedef long long ll;


int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	string s;cin>>s;
	int mini=101;
	rep(i,s.size()){
		if(s[i]=='c'){
			int cnt=0;
			nrep(j,i,s.size()){
				if(s[j]=='w'){
					cnt++;
					if(cnt==2){mini=min(mini,j-i);break;}
				}
			}
		}
	}
	if(mini==101)cout<<-1<<endl;
	else cout<<mini+1<<endl;
	return 0;
}