#include <bits/stdc++.h>
#include <atcoder/all>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace atcoder;
using namespace __gnu_pbds;
using ll=long long;
using ld=long double;
using vll=vector<ll>;
using vvll=vector<vll>;
using pll=pair<ll,ll>;

// using mint=modint;

// template<class K,class V>
// using ordered_map=tree<K,V,less<K>,rb_tree_tag,tree_order_statistics_node_update>;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

    string S;
    cin>>S;
    ll N=S.size();
    vll pref(N,-1),suff(N,-1);

    for(int i=0;i<N;++i){
        if(S[i]=='c')pref[i]=i;
        else if(i>0) pref[i]=pref[i-1];
    }
    for(int i=N-1;i>=0;--i){
        if(S[i]=='w')suff[i]=i;
        else if(i<N-1) suff[i]=suff[i+1];
    }
    ll ans=LLONG_MAX;
    for(int i=1;i<N-1;++i){
        if(S[i]=='w'&&pref[i-1]!=-1&&suff[i+1]!=-1){
            ans=min(ans,suff[i+1]-pref[i-1]+1);
        }
    }

    if(ans==LLONG_MAX)cout<<-1<<endl;
    else cout<<ans<<endl;
}