#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <map>
#include <set>
#include <cstdio>
#include <cmath>
#define rep(i,l,n) for(lint i=l;i<n;i++)
#define rer(i,l,n) for(lint i=l;i<=n;i++)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
using namespace std;
typedef long long lint;
typedef vector<int> vi;
typedef vector<lint> vli;
typedef vector<vi> vvi;
typedef pair<int,int> pii;

int main(){
	string s;
	cin>>s;
	int MIN=1000,f=0,tmp=0;
	rep(i,0,s.size()){
		if(s[i]=='c'){
			f=0;
			tmp=0;
			rep(j,i+1,s.size()){
				if(s[j]=='w') f++;
				if(f==2){
					tmp=j-i+1;
					MIN=min(MIN,tmp);
					break;
				}
			}
		}
	}
	o((MIN==1000?-1:MIN));
}