#include<bits/stdc++.h>
#define ll long long
using namespace std;
map < string,int > a;
void put(){
	printf("ERR\n");
}
int main(){
	ios::sync_with_stdio(false);
	int n;
	string op,ad;
	cin >> n;
	for(int sum = 1; sum <= n; ++sum){
		cin >> op >> ad;
		bool flag=0;
		int len = ad.size(),now = 0,m = 0;
		for(int i = 0;i < ad.size(); ++i){
			if(ad[i] >= '0' && ad[i] <= '9') now = now*10+ad[i]-'0';				
				else if(ad[i] == '.'){
				if(m<3){
					if(now >= 0 && now <= 255) ++m, now = 0;
					else{put();	flag=1; break;}
				}
				else{put();	flag=1; break;}
			}
			else if(ad[i]==':' && m == 3){
				if(now >= 0 && now <= 255) ++m, now = 0;
				else{put(); flag=1; break;}
			}
			else{put(); flag=1; break;}
			if(ad[i] == '0' && now == 0){
				if(ad[i+1] >= '0' && ad[i+1] <= '9'){put(); flag=1; break;}
			}
		}
		if(flag) continue;
		if(now > 65535){put(); continue;}
		if(op == "Server"){	
			if(a[ad] > 0 && a[ad] <= n) printf("FAIL\n");
			else{a[ad] = sum; printf("OK\n");}	
		}
		else{
			if(a[ad] > 0 && a[ad] <= n) cout<<a[ad]<<endl;
			else cout<<"FAIL\n";
		}
	}
    return 0;
}