#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int b = -1, w1 = 0, f = 0;
    string s;
    cin >> s;
    int l = (int)s.size();
    for (int i = 0; i < s.size(); i++){
        if (s[i] == 'c'){
            b = i;
            for (int j = i; j < s.size(); j++){
                if (b != -1 && s[j] == 'w'){
                    w1++;
                }
                if (w1 == 2){
                    l = min(l, j - b + 1);
                    f++;
                    break;
                }
            }
            w1 = 0;
        }
    }
    if (f) cout << l << endl;
    else cout << -1 << endl;
}