#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
#define per(i,n,a) for (int i = n-1;i >= a;i--)
using namespace std;

int main() {
    string S;
    cin >> S;
    int N = S.length();
    int mi = N + 1;
    rep(i, 0, N) {
        if (S[i] == 'c') {
            int w = 0;
            rep(j, i+1, N) {
                if (S[j] == 'w') {
                    w++;
                }
                if (w == 2) {
                    mi = min(mi, j - i + 1);
                    break;
                }
            }
        }
    }
    if (mi == N + 1) mi = -1;
    cout << mi << endl;
    return 0;
}