#include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<cstring>
#include<queue>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double EPS=1e-10;
const int inf=1e9;
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;
int main(){
	string s;
	cin>>s;
	int mi=inf;
	rep(i,s.size())if(s[i]=='c'){
		int co=0;
		loop(j,i+1,s.size())if(s[j]=='w'){
			if(co==0)co++;
			else{
				mi=min(mi,j-i+1);
				break;
			}
		}
	}
	if(mi==inf)mi=-1;
	cout<<mi<<endl;
}