#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;

  int count = 0;

  int start = -1;
  int end = 0;

  int tmp = 0;
  int result = 1e8;
  for(int i = s.size()-1; i >= 0; --i)
  {
    if(s.at(i) == 'w')
    {
      ++count;
      if(count >=2)
        end = tmp;

      tmp = i;
    }

    if(count >=2 && s.at(i) == 'c')
    {
      start = i;
      count = 0;
      result = min(result,end-start+1);
    }
  }

  if(start == -1)
    cout << -1 << endl;
  else
    cout << result << endl;
}