#include <iostream>
#include <vector>
#include <unordered_map>
#include <sstream>
using namespace std;

unordered_map<string, int> mp;

bool check(string str){
    vector<int> a(5, -1);
    sscanf(str.c_str(), "%d.%d.%d.%d:%d", &a[0], &a[1], &a[2], &a[3], &a[4]);
    for (int i = 0; i < 4; i ++ )
        if(a[i] > 255 || a[i] < 0)return false;
    if(a[4] > 65535 || a[4] < 0)return false;
    char b[110];
    sprintf(b, "%d.%d.%d.%d:%d", a[0], a[1], a[2], a[3], a[4]);
    return str == b;
}

int main(){
    int n;
    cin >> n;
    string op, ad;
    for (int i = 1; i <= n; i ++ ){
        cin >> op >> ad;
        if(op == "Server"){
            if(!check(ad)){
                cout << "ERR" << endl;
                continue;
            }
            else if(mp[ad]){
                cout << "FAIL" << endl;
                continue;
            }

            mp[ad] = i;
            cout << "OK" << endl;
        }

        else if (op == "Client"){
            if(!check(ad)){
                cout << "ERR" << endl;
                continue;
            }
            else if(!mp[ad]){
                cout << "FAIL" << endl;
                continue;
            }
            cout << mp[ad] << endl;
        }

    }
    return 0;
}