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

bool ok( string s ){
  int st = 0;
  for( int i = 0; i < s.size(); ++i ){
    if( st == 0 and s[ i ] == 'c' )
      st = 1;
    else if( st == 1 and s[ i ] == 'w' )
      st = 2;
    else if( st == 2 and s[ i ] == 'w' )
      return true;
  } 
  return false;
}

signed main(){
  string s; cin >> s;
  int ans = 1e9;
  for( int i = 0; i < s.size(); ++i )
    for( int j = i; j < s.size(); ++j )
      if( ok( s.substr( i, j - i + 1 ) ) )
        ans = min( ans, j - i + 1 );
  if( ans == ( int ) 1e9 )
    cout << -1 << endl;
  else
    cout << ans << endl;
  return 0;
}