#include<iostream>
#include<algorithm>
#include <vector>
#include<cmath>
#include<iomanip>
using namespace std;
typedef long long int lont;
int main() {
	vector<char>veca(15);
	for (int ia = 0; ia < 14; ia++) {
		cin >> veca.at(ia);
	}
	veca.at(14) = 'x';
	vector<int>vecb(15);
	int cnta = 0;
	int cntb = 0;
	for (int ib = 0; ib < 15; ib++) {
		if (veca.at(ib) == 'o') {
			cnta++;
		}
		else if (veca.at(ib) == 'x') {
			vecb.at(cntb) = cnta;
			cntb++;
			cnta = 0;
		}
	}
	int ans = 0;
	for (int ic = 0; ic < 15; ic++) {
		ans = max(ans,vecb.at(ic)) ;
	}
	cout << ans << endl;
}