#include <bits/stdc++.h>
using namespace std;
#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repl(i,0,n)
#define mp(a,b) make_pair((a),(b))
#define pb(a) push_back((a))
#define all(x) (x).begin(),(x).end()
#define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x))
#define fi first
#define se second
#define dbg(x) cout<<#x" = "<<((x))<<endl
template<class T,class U> ostream& operator<<(ostream& o, const pair<T,U> &p){o<<"("<<p.fi<<","<<p.se<<")";return o;}
template<class T> ostream& operator<<(ostream& o, const vector<T> &v){o<<"[";for(T t:v){o<<t<<",";}o<<"]";return o;}

#define INF 2147483600

int main(){
  string s;
  cin>>s;
  int n = s.size();
  int ans = INF;
  rep(i,n) if(s[i]=='c'){
    int cnt = 0;
    repl(j,i+1,n) if(s[j]=='w'){
      cnt++;
      if(cnt==2) ans = min(ans, j-i+1);
    }
  }
  if(ans == INF) ans = -1;
  cout << ans << endl;
  return 0;
}