#include <iostream>
#include <vector>
#include <string>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#define dump(s) cerr << __LINE__ << "\t:" << #s << " = " << (s) << endl
    
using namespace std;

int main () {
    string s;
    cin >> s;
    const int inf = 1 << 30;
    int ans = inf;
    REP (i, 0, s.size()) {
	if (s[i] != 'c') continue;
	int w = 0;
	REP (j, i + 1, s.size()) {
	    if (s[j] == 'w') w++;
	    if (w == 2) {
		ans = min(ans, j - i + 1);
	    }
	}
    }
    cout << (ans == inf ? -1 : ans) << endl;
    
    return 0; 
}