#include<bits/stdc++.h>
using namespace std;
bool ok(string t){
	vector<string>v;
	string s;
	t.push_back('-');
    long long c1 = 0, c2 = 0;
	for(long long i=0; i<t.size(); i++){
		if(t[i]=='.' || t[i]==':' || t[i]=='-'){
            if(t[i] == '.')c1++;
            if(t[i] == ':')c2++;
			if(!s.empty()) v.push_back(s);
			s.clear();
		}else s+=t[i];
	}
    if(c1!=3 || c2 != 1)return 0;
	if(v.size() != 5)return 0;

	for(long long i=0; i<4; i++){
		string w = v[i];
		if(w.size() != 1 && w[0] == '0')return 0;
		int x = stoll(v[i]);
		if(x<0 || x>255)return 0;
	}
	string w = v[4];// e
	if(w.size() != 1 && w[0] == '0')return 0;
	int x = stoll(w);
	if(x<0 || x>65535)return 0;
	return 1;
}
int main(){
    long long n;
    map<string,long long>se;
	cin>>n;
	for(long long i=1;i<=n;i++){
		string s,s2;
		cin>>s>>s2;
		if(ok(s2)){
			if(s=="Server"){
				if(se.count(s2)){
					cout<<"FAIL"<<endl;
				}
				else{
					se[s2]=i;
					cout<<"OK"<<endl;
				}
			}
			else{
				if(se.count(s2)) cout<<se[s2]<<endl;
				else cout<<"FAIL"<<endl;
			}
		}
		else{
			cout<<"ERR"<<endl;
		}
	}
}