#include <iostream>
#include <iomanip>
typedef unsigned long long ul;
typedef signed long long ll;

int main(void)
{
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);
  std::cout << std::fixed << std::setprecision(2);
  std::string s;
  std::cin >> s;
  int ans = s.size()+1;
  for (int i = 0; i < s.size(); ++i) {
    if (s[i]!='c') continue;
    int w = 0;
    for (int j = i+1; j < s.size(); ++j) {
      if (s[j]=='w') w++;
      if (w==2) {
        ans = std::min(ans, j-i+1);
        break;
      }
    }
  }
  std::cout << (ans == s.size()+1 ? -1 : ans) << std::endl;
  return 0;
}