#include<bits/stdc++.h>
using namespace std;
long long num[15];
int cnt;  //已有的服务器个数
pair<string, int> ip[1005]; //服务器地址和编号
inline bool isnum(char ch) { //判断是否是数字
	return ch >= '0' && ch <= '9';
}
bool judge(string s) {
	memset(num, 0, sizeof(num));
	int c1, c2, ind;//c1:'.'个数 c2:':'个数
	c1 = c2 = ind = 0;
	bool f = 1;
	for (int i = 0; i < s.size(); ++i) {
		if (isnum(s[i])) {
			if (s[i] == '0' && f && isnum(s[i + 1])) return 0; //判断前导0
			num[ind] = num[ind] * 10 + s[i] - '0';
			f = 0;
			continue;
		}
		if (s[i] == '.') {
			++c1;
			++ind;
			f = 1;
			continue;
		}
		if (s[i] == ':') {
			++c2;
			++ind;
			f = 1;
			continue;
		}
		return 0;
	}
	if (ind != 4 || c1 != 3 || c2 != 1 || num[0] > 255 || num[1] > 255 || num[2] > 255 || num[3] > 255 || num[4] > 65535) return 0;
	return 1;
}
int find(string s) {
	for (int i = 0; i < cnt; ++i)
		if (s == ip[i].first) return i;
	return -1;
}
int main() {
	cin.tie(0);
	cout.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;
	for (int k = 0; k < n; ++k) {
		string op, ad;
		cin >> op >> ad;
		if (judge(ad)) {
			if (op == "Server") {
				if (find(ad) != -1) cout << "FAIL" << endl;
				else {
					ip[cnt++] = make_pair(ad, k + 1);
					cout << "OK" << endl;
				}
			} else {
				int d = find(ad);
				if (d == -1) cout << "FAIL" << endl;
				else cout << ip[d].second << endl;
			}
		} else cout << "ERR" << endl;
	}
	return 0;
}