#include<bits/stdc++.h>
using namespace std;
int main()
{
	char c;
	bool f=1;
	string s="";
	while(cin>>c)
	{
		if(c==',')
		{
			if(f&&s.size()>=6&&s.size()<=12) cout<<s<<endl;
			f=1;
			s="";
			continue;
		}
		s+=c;
		if(c>='A'&&c<='Z') continue;
		if(c>='a'&&c<='z') continue;
		if(c>='0'&&c<='9') continue;
		if(c=='!'||c=='@'||c=='#'||c=='$') continue;
		f=0;
	}
	return 0;
}