#include<bits/stdc++.h>
using namespace std;
int main()
{
	string s;
	cin>>s;
	string s1="oxx";
	string res;
	for(int i=1;i<=5;i++)
	{
		res=res+s1;
	}
	if(res.find(s)!=-1) cout<<"Yes";
	else cout<<"No";  
	return 0;
}