#include<bits/stdc++.h>
using namespace std;
map<string,int>m;
bool check(string s)
{
	int c=1,t=-1;
	s+='.';
	for(int i=0;i<s.size();i++)
	{
		if(isdigit(s[i]))
		{
			if(t<0)
				t=0;
			if(s[i]=='0'&&t<=0&&isdigit(s[i+1]))
				return 0;
			t=t*10+s[i]-'0';
		}
		else
		{
			if(s[i]!=((c==4)?':':'.')||t>((c==5)?65535:255)||c>5||t==-1)
				return 0;
			t=-1;
			c++;
		}
	}
	return c==6;
}
int main()
{
	int n;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		string mo,ip;
		cin>>mo>>ip;
		if(!check(ip))
		{
			cout<<"ERR\n";
			continue;
		}
		if(mo=="Server")
		{
			if(m.count(ip))
				cout<<"FAIL\n";
			else
			{
				m[ip]=i;
				cout<<"OK\n";
			}
		}
		else
		{
			if(m.count(ip))
				cout<<m[ip]<<'\n';
			else
				cout<<"FAIL\n";
		}
	}
}