#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <climits>
#include <cassert>
#include <cmath>
using namespace std;

#define REP(i,n) for(int i=0;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define INF INT_MAX/3
#define LINF LLONG_MAX/3
#define MP make_pair
#define PB push_back
#define EB emplace_back
#define ALL(v) (v).begin(),(v).end()
#define debug(x) cout<<#x<<":"<<x<<endl
#define debug2(x,y) cout<<#x<<","<<#y":"<<x<<","<<y<<endl

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;

int main(){
    string s;cin>>s;
    int n=s.size();
    int ans=INF;
    for(int i=0;i<n;i++) if(s[i]=='c'){
        int c=0;
        for(int j=i+1;j<n;j++) if(s[j]=='w'){
            c++;
            if(c==2) ans=min(ans,j-i+1);
        }
    }
    if(ans==INF) cout << -1 << endl;
    else cout << ans << endl;
    return 0;
}