#include <iostream>

using namespace std;

int main() {
	
	string s;
	cin >> s;
	int ans = 0;
	int w = 0;
	bool f = false;
	int l = s.size();
	for(int i = 0; i < l; i++) {
		if(s[i] == 'c') {
			
			if(f) {
			    ans = 0;
			    w = 0;
			}
			
			f = true;
			
		}
		if(f){
		    ans++;
		    if(s[i] == 'w') {
				w++;
			}
			
			if(w == 2)break;
		    
		}
	}
	if(ans == 0)cout << -1;
	else cout << ans;
	
}