#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<map>
#include<queue>
#include<string>
#include<sstream>
#include<cmath>
using namespace std;

int main(){

  string s;
  cin >> s;

  // bool fl = false;
  int ans = 100;
  for(int i=0; i<s.size(); i++){
    int w = 0;
    int cnt = 0;
    if( s[i] == 'c' ){
      for(int j=i; j<s.size(); j++){
        if( s[j] == 'w' ) w++;
        cnt++;
        if( w == 2 ) break;
      }
    }
    if( ans > cnt && cnt != 0 && w == 2 ) ans = cnt;
  }
  if( ans != 100 ) cout << ans << endl;
  else cout << -1 << endl;


  return 0;
}