#include <iostream>
using namespace std;

int main() {
    string s;
    cin >> s;
    int ans = 101;
    int S = s.size(), w1 = S, w2 = S;
    for(int i = S - 1; i >= 0; i--){
        if(s[i] == 'w'){
            w1 = w2;
            w2 = i;
        }
        if(s[i] == 'c' && w1 != S){
            ans = min(ans, w1 - i + 1);
        }
    }
    if(ans == 101)cout << -1 << endl;
    else cout << ans << endl;
    return 0;
}