#include <iostream>
#include <string>
using namespace std;
int main() {
	string C;
	cin >> C;
	int MaxCount = 0;
	int Count = 0;
	for (int i = 0; i < 14; i++) {
		if (C[i] == 'o') {
			Count++;
		}
		if (C[i] == 'x') {
			if (Count > MaxCount) {
				MaxCount = Count;
			}
			Count = 0;
		}
	}
	if (Count > MaxCount)MaxCount = Count;
	cout << MaxCount << endl;
	return 0;
}