#include<iostream>
using namespace std;
int main(void){
	int v[14], ans = 0, sum = 0; char c;
	for (int i = 0; i < 14; i++){
		cin >> c;
		if (c == 'o'){ sum++; }
		else{ sum = 0; }
		if (sum > ans) ans = sum;
	}
	cout << ans << endl;
	return 0;
}