#include <iostream>
#include <string>
#include <cmath>
using namespace std;

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

    float ans = INFINITY;
    for(int i = 0; i < s.length(); i++){
        if(s[i] == 'c'){
            int cou = 0;
            int flag = 0;
            for(int j = i; j < s.length(); j++){
                cou++;
                if(s[j] == 'w') flag++;
                if(flag == 2){
                    if(cou >= 3 && cou < ans) ans = cou;
                    break;
                }
            }
        }
    }
    
    if(ans == 0)
        cout << -1 << endl;
    else
        cout << ans << endl;

    return 0;
}