#include<bits/stdc++.h>
using namespace std;
int n;
string name;
char s[10000];
map<string,long long>mp;
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>name;
		int a=-1,b=-1,c=-1,d=-1,e=-1;
		int t=sscanf(s,"%d.%d.%d.%d:%d",&a,&b,&c,&d,&e);
		if(t!=5||a<0||a>255||b<0||b>255||c<0||c>255||d<0||d>255||e<0||e>65535){
			cout<<"ERR"<<endl;
			continue;
		}else if(name[0]=='S'){
			if(mp[s]){
				cout<<"FALL"<<endl;
				continue;
			}
			mp[s]=i;
			cout<<"OK";
		}else if(name[0]=='C'){
			if(!mp[s]){
				cout<<"FALL"<<endl;
				continue;
			}
			cout<<mp[s];
		}
	}
	return 0;
}

输入：

5
Server 192.168.1.1:8080
Server 192.168.1.1:8080
Client 192.168.1.1:8080
Client 192.168.1.1:80
Client 192.168.1.1:99999

运行：

5
Server 192.168.1.1:8080
ERR
ERR
Server 192.168.1.1:8080
ERR
ERR
Client 192.168.1.1:8080
ERR

三台计算机去那了? 为什么消失了？