#include<bits/stdc++.h>
using namespace std;
bool tmp(string s)
{
	if(s!="0"&&s[0]=='0') return false;
	return true;
}
bool check(string s)
{
	int point=0;
	int moup=0;
	if(s[0]=='.') return false; 
	int mou=0;
	for(int i=0;i<int(s.size());i++)
	{
		if(s[i]=='.'&&s[i+1]=='.') return false;
		if(s[i]=='.') point++;
		if(s[i]==':') mou++;
		if(s[i]==':'&&point==3) moup++;
	}
	if(point!=3&&moup!=1&&mou!=1) return false;
	int a=0,b=0,c=0,d=0,e=0;
	int i=0;
	string s1,s2,s3,s4,s5;
	while(s[i]!='.')
	{
		a=a*10+s[i]-'0';
		s1+=s[i];
		i++;
	}
	i++;
	while(s[i]!='.')
	{
		b=b*10+s[i]-'0';
		s2+=s[i];
		i++;
	}
	i++;
	while(s[i]!='.')
	{
		c=c*10+s[i]-'0';
		s3+=s[i];
		i++;
	}
	i++;
	while(s[i]!=':')
	{
		d=d*10+s[i]-'0';
		s4+=s[i];
		i++;
	}
	i++;
	while(i<int(s.size()))
	{
		e=e*10+s[i]-'0';
		s5+=s[i];
		i++;
	}
	//cout<<s5<<endl;
	//cout<<a<<" "<<b<<" "<<c<<" "<<d<<" "<<e<<endl;
	if(a<0||a>255||b<0||b>255||c<0||c>255||d<0||d>255||e<0||e>65535||!tmp(s1)||!tmp(s2)||!tmp(s3)||!tmp(s4)||!tmp(s5)) return false;
	return true;
}
int main()
{
	//freopen("network.in","r",stdin);
    //freopen("network.out","w",stdout);
    map<string,int> mp;
    int t;
    cin>>t;
    for(int i=1;i<=t;i++)
    {
		string s;
		cin>>s;
		string s1;
		cin>>s1;
		if(!check(s1)) cout<<"ERR"<<endl;
		else
		{
			if(s=="Server")
			{
				if(mp[s1]!=0) cout<<"FAIL"<<endl;
				else
				{
					mp[s1]=i;
					cout<<"OK"<<endl;
				}
			}	
			else
			{
				if(mp[s1]==0) cout<<"FAIL"<<endl;
				else cout<<mp[s1]<<endl;
			}
		}
    }
	return 0;
}

cmp算前导零

check 判合法

RE