#include<iostream>
#include<string>
#include<cstring>
#include<complex>
#include<vector>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<iomanip>
using namespace std;

#define REP(i, j) for (int i = 0; i < (int)j; ++i)
#define FOR(i, j, k) for (int i = (int)j; i < (int)k; ++i)
#define SORT(v) sort(v.begin(), v.end())
#define REVERSE(v) reverse(v.begin(), v.end())
typedef complex<double> P;
typedef vector<int> VI;
typedef long long LL;
typedef pair<int,int> PII;

string s;

int find_cww(int ci) {
	int wcnt = 0;
	FOR(i,ci,s.length()) {
		if (s[i] == 'w') wcnt++;
		if (wcnt == 2) {
			return (i - ci + 1);
		}
	}

	return 101;
}

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

	cin >> s;

	VI ans;
	ans.push_back(101);

	REP(i,s.length()) {
		if (s[i] == 'c') {
			ans.push_back(find_cww(i));
		}
	}

	SORT(ans);
	if (ans[0] == 101) cout << -1 << endl;
	else cout << ans[0] << endl;

	return 0;
}