#include <bits/stdc++.h>
using namespace std;
int n;
string a,b;
map < string,int > m;
bool hefa(string a)
{
	string bd="";
	if(a[0]=='0' && a[1]!='.')
		return false; 
	int s=0,ans[7]={0},ss=0,t=0;
	for(int i=0;i<a.size();i++)
	{
		if(a[i]!='.' && a[i]!=':')
			s=s*10+(a[i]-'0');
		else
		{
			bd+=a[i];
			if(a[i+1]=='0' && a[i+2]!='.' && a[i+2]!=':')
				return false;
			ans[++t]=s;
			s=0;
			ss++;
		}
	}
	ans[++t]=s;
	ss++;
	if(ss!=5 || ans[1]>255 || ans[2]>255 || ans[3]>255 || ans[4]>255 || ans[5]>65535 || bd!="...:")
		return false;
	return true;
}
int main()
{
	ios::sync_with_stdio(false);
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a>>b;
		if(!hefa(b))
			cout<<"ERR"<<endl;
		else
		{
			if(a=="Server")
			{
				if(m.count(b)==0)
				{
					m[b]=i;
					cout<<"OK"<<endl;
				}
				else
					cout<<"FAIL"<<endl;
			}
			else
			{
				if(m.count(b)==0)
					cout<<"FAIL"<<endl;
				else
					cout<<m[b]<<endl;
			}
		}
	}
	return 0;
}