#include <bits/stdc++.h>
using namespace std;
using ll=long long;

#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define RREP(i,m,n) for(int i=(int)(m);i>=(int)(n);--i)
#define debug(x) cout << #x << "=" << (x) << endl;

template<class T> inline bool chmin(T& a,T b){if(a>b){a=b;return true;}return false;}
template<class T> inline bool chmax(T& a,T b){if(a<b){a=b;return true;}return false;}
template<typename T> void fail(T v){cout << v << endl;exit(0);}
//template end

void solve(){
  string str;
  cin>>str;
  int res=INT_MAX;
  string s="cww";
  rep(i,str.size()-1)
    REP(j,i+1,str.size()){
      int idx=0;
      REP(k,i,j+1)
        if(s[idx]==str[k]){idx++;if(idx==3)break;}
      if(idx==3)chmin(res,j-i+1);
    }
  if(res==INT_MAX)
    cout<<-1<<endl;
  else cout<<res<<endl;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  return 0;
}