#include<algorithm>
#include<complex>
#include<ctype.h>
#include<iomanip>
#include<iostream>
#include<fstream>
#include<map>
#include<math.h>
#include<numeric>
#include<queue>
#include<set>
#include<stack>
#include<stdio.h>
#include<string>
#include<string>
#include<vector>

using namespace std;
typedef long long ll;

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

template < typename T >
void vprint(T &V){
	for(auto v : V){
    	cout << v << " ";
	}
	cout << endl;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    string s;
    cin >> s;

    vector<ll> C;
    vector<ll> W;

    FOR(i, 0, s.size()){
        char c = s[i];
        if(c=='c'){
            C.push_back(i);
        }else if(c=='w'){
            W.push_back(i);
        }
    }

    ll min_len = inf;
    for(ll c_index : C){
        auto it = upper_bound(ALL(W), c_index);
        if(it!=W.end()){
            it++;
            if(it!=W.end()){
                ll len = *it - c_index + 1;
                min_len = min(min_len, len);
            }
        }
    }

    if(min_len==inf){
        p(-1);
    }else{
        p(min_len);
    }
    
    return 0;
}