#include "bits/stdc++.h"
using namespace std;
#define print(x) cout<<x<<endl;
#define rep(i,a,b) for(int i=a;i<b;i++)
#define REP(i,a) for(int i=0;i<a;i++)
typedef long long ll;
typedef pair<int, int> PI;
typedef pair<int, PI> V;
typedef vector<int> VE;
const ll mod = 100000000000;

using namespace std;

int main() {
  string s;
  int cnt=0,len;
  int a=101;
  cin>>s;
  while(s.find('c')!=-1){
    cnt=0;
    rep(i,s.find('c'),s.length()){
      if(s[i]=='w')cnt+=1;
      if(cnt==2){
        len=i-s.find('c')+1;
        a=min(a,len);
        break;
      }
    }
    s.replace(s.find('c'),1,"*");
  }
  if(a!=101){cout<<a<<endl;}
  else {cout<<-1<<endl;}
}