#include <bits/stdc++.h>
#define int long long
using namespace std;

signed main(){
  string S;
  cin >> S;
  
 
  int ans = 10000000;
  for( int i = 0; i < S.size(); i++ ){
    if( S.at(i) == 'c' ){
      int cnt = 1;
      bool fg1 = false;
      for( int j = i+1; j < S.size(); j++ ){
        cnt++;
        if( S.at(j) == 'w' && fg1 == false ) fg1 = true;
        else if( S.at(j) == 'w' && fg1 == true ) ans = min(cnt, ans);
      }
    }
  }
  if( ans != 10000000 ) cout << ans << endl;
  else cout << -1 << endl;
}