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

/*** O(N^2) ver. ***/

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#define pb push_back
#define ALL(a) (a).begin(),(a).end()

int main() {
    string S;
    cin >> S;
    int N = S.length();
    int mi = N + 1;
    REP(i, N) {
        if (S[i] == 'c') {
            int w = 0;
            FOR(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;
}