#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

int main()
{
    string s; cin >> s;

    int ans = 1000;
    rep(i, 0, s.length()) rep(j, i + 1, s.length()) rep(k, j + 1, s.length())
    {
        if (s[i] == 'c' && (s[j] == 'w' && s[k] == 'w'))
        {
            ans = min(ans, k - i + 1);
        }
    }
    if (ans == 1000) ans = -1;
    cout << ans << endl;
}