建议通过[洛谷翻译](https://CF1531A Зингер | color - 洛谷 | 计算机科学教育新生态 (luogu.com.cn))了解大意

CODE：

#include<bits/stdc++.h>
using namespace std;
int N;
bool locked=false;
string res,now;
int main ()
{
    res="blue";
	cin>>N;
    while (N--)
	{ 
		cin>>now;
        if(now[0]=='l' && now[1]=='o' && now[2]=='c' && now[3]=='k') 
		{
			locked=true;
			continue;
		}
        if(now[0]=='u' && now[1]=='n' && now[2]=='l' && now[3]=='o' && now[4]=='c' && now[5]=='k')
		{
			locked=false;
			continue;
		}
        if(locked) continue;res=now; 
    }
    cout<<res<<endl;
    return 0;
}