#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#ifdef __unix__
#include <bits/stdc++.h>
#else
#include "bits\stdc++.h"
#endif
#include <vector>
#include <set>
#include <string>
#include <queue>
#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define SIZE 10

enum Muki{
  up,r,down,l
};


int main() {
  int i,j;
  cin.tie(0);
  ios::sync_with_stdio(false);
  char s[200];
  int min_cww = INT_MAX;
  cin >> s;
  for(i=0;s[i];i++) {
    if(s[i] == 'c') {
      int cnt = 0;
      for(j=i;s[j];j++) {
        if(s[j] == 'w') cnt++;
        if(cnt == 2) break;
      }
      if(s[j] != 0) {
        min_cww = min(j-i+1,min_cww);
      }
    }
  }
  if(min_cww != INT_MAX) {
    cout << min_cww << endl;
  }
  else cout << -1 << endl;
  return 0;
}