#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int main(){
    string S;
    while(cin >> S){
        int N = sz(S), ans = 1000;
        rep(i, N)if(S[i]=='c'){
            for(int j = i + 2; j < N; ++j)if(S[j]=='w'){
                FOR(k, i + 1, j){
                    if(S[k] == 'w'){
                        smin(ans, j - i + 1);
                        break;
                    }
                }
            }
        }
        if(ans == 1000)ans = -1;
        cout << ans << endl;
    }
}