#include <iostream>
#include <algorithm>
using namespace std;
using i64 = long long;

template<typename T>
class Range{private:struct I{T x;T operator*(){return x;}bool operator!=(I& lhs){return x<lhs.x;}void operator++(){++x;}};I i,n;
public:Range(T n):i({0}),n({n}){}Range(T i,T n):i({i}),n({n}){}I& begin(){return i;}I& end(){return n;}};
using range = Range<int>;

const int inf = 2000;

int main(void) {
  string s; cin >> s;
  int n = s.size();
  int lag = inf;
  for(auto&& i : range(n)) {
    for(auto&& j : range(i+1, n)) {
      for(auto&& k : range(j+1, n)) {
        if(s[i] == 'c' && s[j] == 'w' && s[k] == 'w') {
          lag = min(lag, k-i+1);
        }
      }
    }
  }
  if(lag == inf) { lag = -1; }
  printf("%d\n", lag);
  return 0;
}