#pragma region Macros

#include <bits/extc++.h>
using namespace std;
using namespace __gnu_pbds;
// using namespace __gnu_cxx;

#define TO_STRING(var) # var
#define pb emplace_back
#define int ll
#define endl '\n'

using ll = long long;
using ld = long double;
const ld PI = acos(-1);
const ld EPS = 1e-10;
const int INF = 1 << 30;
const ll INFL = 1LL << 62;
// const int MOD = 998244353;
const int MOD = 1000000007;

int ceil(int x, int y) {return (x > 0 ? (x + y - 1) / y : x / y);}
int POW(int x, int y) {
    if (y != (int)(y) or y < 0 or x != 0 && x != 1 && y > 64) {cout << "Error" << endl;return 0;}
    if (y == 0) return 1;
    if (y % 2 == 0) return POW(x * x, y / 2);
    return x * POW(x, y - 1);
}

__attribute__((constructor))
void constructor() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
}

#pragma endregion

signed main() {
    string S;
	cin >> S;
	int N = S.size();

	int ans = INF;
	for (int i = 0; i < N; i++) {
		if (S[i] == 'c') {
			int cnt = 1;
			int cur = i + 1;
			bool flagw1 = true, flagw2 = true;
			while (cur != N && (flagw1 or flagw2)) {
				if (flagw1 == false && S[cur] == 'w') flagw2 = false;
				if (S[cur] == 'w') flagw1 = false;
				cur++;
				cnt++;
			}
			if (flagw1 == false && flagw2 == false) ans = min(ans, cnt);
		}
	}
	if (ans == 0 or ans == INF) { cout << -1 << endl; return 0; }
	cout << ans << endl;
}