#include <bits/stdc++.h>
#define FOR(i,a,b) for(int i = (a); i < (b); ++i)
#define REP(i,n) FOR(i,0,n)
#define SZ(n) (int)(n).size()
#define ALL(n) (n).begin(), (n).end()
using namespace std;
typedef long long LL;
typedef vector<int> VI;

int main() {
	string s;
	cin >> s;
	int ans = 101;
	int t = 0;
	REP(i, s.length()) {
		if (s[i] == 'c') {
			t = 0;
			for (int j = i + 1; s[j]; ++j) {
				if (s[j] == 'w') t++;
				if (t == 2) {
					ans = min(ans, j - i + 1);
					break;
				}
			}
		}
	}
	cout << ((ans == 101) ? -1 : ans) << endl;
	return 0;
}