#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<int(n); i++)
#define FOR(i,m,n) for(int i=int(m); i<int(n); i++)
#define ALL(obj) (obj).begin(),(obj).end()
#define VI vector<int>
#define VLL vector<long long>
#define VVI vector<vector<int>>
#define VVLL vector<vector<long long>>
#define VC vector<char>
#define VS vector<string>
#define VVC vector<vector<char>>
#define fore(i,a) for(auto &i:a)
typedef long long ll;
typedef pair <int, int> P;
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }
const int  INF = 2147483647;
const ll INFL = 9223372036854775807;
const ll mod = 1000000007;



int main() {
	string s;
	cin >> s;
	VI c, w;
	REP(i, s.size()) {
		if (s[i] == 'c')c.push_back(i);
		else if (s[i] == 'w')w.push_back(i);
	}
	int ans = INF;
	REP(i, c.size()) {
		bool a = true;
		REP(j, w.size()) {
			if (c[i] < w[j]) {
				if (a)a = false;
				else ans = min(ans, w[j] - c[i] + 1);
			}
		}
	}
	if (ans == INF)cout << -1 << endl;
	else cout << ans << endl;
	return 0;
}