#include <algorithm>
#include <iostream>
#include <iomanip>
#include <limits.h>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
#include <stack>

using namespace std;
#define rep(i, n) for (int i = 0; i < n; i++)
#define rep1(i, n) for (int i = 1; i < n + 1; i++)
#define all(A) A.begin(), A.end()
#define itr(A, l, r) A.begin() + l, A.begin() + r
#define debug(var) cout << #var << " = " << var << endl;
typedef long long ll;

int main(void)
{
    string s;
    cin >> s;
    int n = s.size();
    vector<int> w_sum(n + 1);
    rep(i, n)
    {
        w_sum[i + 1] = w_sum[i] + (s[i] == 'w');
    }
    auto print_vector = [](auto v)
    {
        for (auto i : v)
        {
            cout << i << ',';
        }
        cout << endl;
    };
    // print_vector(w_sum);
    int ans = n + 1;
    rep(i, n)
    {
        if (s[i] != 'c')
        {
            continue;
        }
        auto itr = lower_bound(w_sum.begin() + i, w_sum.end(), w_sum[i] + 2);
        if (itr == w_sum.end())
        {
            continue;
        }
        int where = itr - w_sum.begin();
        auto chmin = [](auto &a, auto b)
        { a = min(a, b); };
        chmin(ans, where - i);
    }
    if (ans > n)
    {
        cout << -1 << endl;
    }
    else
    {
        cout << ans << endl;
    }
}