#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi  = vector<int>; using vb  = vector<bool>; using vd  = vector<double>; using vl  = vector<ll>;
using vvi = vector<vi>;  using vvb = vector<vb>;   using vvd = vector<vd>;     using vvl = vector<vl>;

#define REP(i,n) for(ll i=0; i<(n); ++i)
#define FOR(i,b,n) for(ll i=(b); i<(n); ++i)

int main() {
	string s; cin >> s;
	
	vl index_c;
	vl index_w;
	REP(i, s.size()) {
		if (s[i] == 'c') index_c.push_back(i);
		if (s[i] == 'w') index_w.push_back(i);
	}
	ll ans = 1001;
	for (ll i : index_c) {
		ll cnt = 0;
		for (ll j : index_w) if (j>i) if (++cnt == 2) {
			ans = min(ans, j - i + 1);
			break;
		}
	}

	cout << (ans==1001 ? -1 : ans) << endl;
	
	return 0;
}