#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <stack>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

int main(){
  ios::sync_with_stdio(false);
  string str;
  cin >> str;

  int ret = 100000;
  rep(i,str.length()){
    if(str[i] == 'c'){
      int len = 1;
      int w = 0;
      REP(j,i+1,str.length()){
        len++;
        if(str[j] == 'w'){
          w++;
          if(w == 2){
            ret = min(ret, len);
            break;
          }
        }
      }
    }
  }
  if(ret > 100){
    cout << -1 << endl;
  }else{
    cout << ret << endl;
  }
  
  return 0;
}