#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    string s;
    cin >> s;
    int ans = 1001001001;
    int n = s.size();
    rep(i,n){
        int flag = 0;
        srep(j,i,n){
            if(flag == 0 && s[j] == 'c')flag = 1;
            if(flag == 2 && s[j] == 'w'){
                ans = min(ans, j - i + 1);
                break;
            }
            if(flag == 1 && s[j] == 'w')flag = 2;
        }
    }

    if(ans > 1001001)ans = -1;
    cout << ans << endl;
    return 0;
}