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

Int lcs(string X,string Y){
  const Int N=max(X.size(),Y.size())+1;
  vector<vector<Int> > c(N,vector<Int>(N,0));
  Int m = X.size();
  Int n = Y.size();
  Int maxl = 0;
  X = ' ' + X;
  Y = ' ' + Y;
  for(Int i=1;i<=m;i++){
    for(Int j=1;j<=n;j++){
      if(X[i]==Y[j]) c[i][j]=c[i-1][j-1]+1;
      else c[i][j]=max(c[i-1][j],c[i][j-1]);
      maxl=max(maxl,c[i][j]);
    }
  }
  return maxl;
}


template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  string b="cww";
  string s;
  cin>>s;
  Int n=s.size();
  Int ans=n+1;
  for(Int i=0;i<n;i++){
    for(Int j=1;i+j<=n;j++){
      string t=s.substr(i,j);
      if(lcs(b,t)==3) chmin(ans,j);
    }
  }
  if(ans>n) ans=-1;
  cout<<ans<<endl;
  return 0;
}