//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int main(){
  string S; cin >> S;
  int siz = (int)S.size();
  vector<int> c, w;
  
  for(int i = 0; i < siz; i++){
    if(S[i] == 'c') c.push_back(i);
    if(S[i] == 'w') w.push_back(i);
  }
  
  int ans = 1e9;
  for(int i = 0; i < (int)c.size(); i++){
    int now = 0;
    
    for(int j = 0; j < (int)w.size(); j++){
      if(c[i] < w[j]) now++;
      
      if(now == 2){
        ans = min(ans, w[j]-c[i]+1);
        continue;
      }
    }
  }
  
  ans != 1e9 ? printl(ans) : printl(-1);
  
  return 0;
}