#include<bits/stdc++.h>
using namespace std;
int n;
string op[100],ad[100];
bool check(string s){
    int l=s.size(),dian=0,maohao=0,abcde=0;
    long long tmp=0; 
    for(int i=0;i<l;i++){
        if((i==0 || (s[i-1]=='.'||s[i-1]==':')) && s[i]>='0' && s[i]<='9') abcde++;
        if(s[i]=='.'||s[i]==':'){
            if(s[i]=='.') dian++;
            else if(s[i]==':') maohao++;
            if(dian<3 && maohao) return false;
            if(abcde==0) return false;
            if(0<=tmp && tmp<=255){
                tmp=0;
                continue;
            }
            else return false;
        }
        else if(s[i]<'0'||s[i]>'9') return false;
        if(i && tmp==0 && s[i-1]=='0') return false;
        tmp=tmp*10+s[i]-'0';
    }
    if(dian!=3 || maohao!=1 || abcde!=5) return false;
    if(0<=tmp && tmp<=65535) return true;
    else return false;
}
int find(int i){
	int j=1;
	for(j=1;j<i;j++){
		if(ad[j]==ad[i]) return j;
	}
	return -1;
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++) cin>>op[i]>>ad[i];
    for(int i=1;i<=n;i++){
        if(!check(ad[i])) cout<<"ERR"<<endl;
        else if(op[i]=="Server"){
            if(find(i)==-1) cout<<"OK"<<endl;
            else cout<<"FAIL"<<endl;
        }
        else if(op[i]=="Client"){
        	int f=find(i);
            if(f!=-1) cout<<f<<endl;
            else cout<<"FAIL"<<endl;
        }
    }
    return 0;
}