#include <bits/stdc++.h>
using namespace std;

int main()
{
	string S;
	cin >> S;

	vector<int> cc;
	vector<int> ww;
	for( int i = 0; i < S.size(); i++ ) {
		if( S[i] == 'c' ) cc.push_back( i );
		if( S[i] == 'w' ) ww.push_back( i );
	}
	int ans = 101;
	for( int i = 0; i < (int)cc.size(); i++ ) {
		int st = cc[i];
		for( int j = 0; j < (int)ww.size() - 1; j++ ) {
			if( ww[j] < st ) continue;
			for( int k = j + 1; k < (int)ww.size(); k++ ) {
				int end = ww[k];
				ans = min( ans, end - st + 1 );
			}
		}
	}
	if( ans == 101 ) ans = -1;

	cout << ans << endl;
}