#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<ll>;
using vs = vector<string>;
#define  rep(i,n) for(ll i = 0; i < (n); ++i)
#define  red(i,n) for(ll i = (n)-1; i >= 0; --i)
#define  all(a)   begin(a),end(a)
#define  pb(a)    push_back(a)
#define  yn       cout<<"Yes\n"; else cout<<"No\n";
inline ll gcd(ll a,ll b) { return b?gcd(b,a%b):a; }
const int INF=1000000009;
const ll LINF = 1e18;


int main()
{
    string s;
    cin>>s;
    int a=s.size();
    rep(i,a)if(s[i]=='c')for(int j=a-1;j>=i;j--)if(s[j]=='w')for(int k=i+1;k<j;k++)if(s[k]=='w')cout<<j-i+1<<endl,exit(0);
    cout<<-1<<endl;

    return 0;
}