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

#define rep(i,n) for(int i = 0; i < (int)(n); ++i)

string s;

int main(){
    while(cin >> s){
        int ans = 1e9;
        rep(i,s.size())rep(j,i)rep(k,j){
            if(s[k] == 'c' && s[j] == 'w' && s[i] == 'w'){
                ans = min(ans, i-k+1);
            }
        }
        if(ans == 1e9) ans = -1;
        cout << ans << endl;
    }
}