#include <iostream>
#include <string>
#include <cmath>
using namespace std;

int main(){
   int ans = -1;
   string s;
   cin >> s;
   for(int i = 0;i < s.size();i++) if(s[i] == 'c') for(int j = i + 1;j < s.size();j++) if(s[j] == 'w') for(int k = j + 1;k < s.size();k++) if(s[k] == 'w') ans = min(ans,k - i);
   cout << ans << endl;
}