#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <list>
#include <functional>
#include <queue>
#include <map>
#include <iterator>
#include <iomanip>
#include <complex>
#include <cctype>
using namespace std;

using ull = unsigned long long;
using ll = long long;


int main()
{
  string s;
  cin >> s;

  char data[3] = { 'c','w','w'};
  int count = 0;

  int start = 0;
  int end = 0;

  for(int i = 0; i < s.size(); ++i)
  {
    if(s.at(i) == data[count])
    {
      if(count == 0)
        start = i;
      else if(count == 2)
        end = i;
      ++count;
    }
  }

  if(end == 0)
    cout << -1 << endl;
  else
    cout << end -start+1 << endl;
}