#include <bits/stdc++.h>
using namespace std;
map<string,int>m;
signed main(){
	ios::sync_with_stdio(false);
	int n;
	cin>>n;
	for(int i=1;i<=n;i++){
		string na,x;
		cin>>na>>x;
		int a[5],b;
		if(sscanf(x.c_str(),"%d.%d.%d.%d:%d",&a[1],&a[2],&a[3],&a[4],&b)!=5){
			cout<<"ERR"<<endl;
			continue;
		}
		char y[30];
		sprintf(y,"%d.%d.%d.%d:%d",a[1],a[2],a[3],a[4],b);
		if(y!=x){
			cout<<"ERR"<<endl;
			continue;
		}
		bool f=1;
		for(int i=1;i<=4;i++)
			if(a[i]<0||a[i]>255){
				cout<<"ERR"<<endl;
				f=0;
				break;
			}
		if(!f)continue;
		if(b<0||b>65535){
			cout<<"ERR"<<endl;
			continue;
		}
		if(na[0]=='S'){
			if(m.count(x))
				cout<<"FALL"<<endl;
			else
				cout<<"OK"<<endl,m[x]=i;
		}else{
			if(m.count(x))
				cout<<m[x]<<endl;
			else
				cout<<"FALL"<<endl;
		}
	}
	return 0;
}