#include<stdio.h>
#include<string.h>
int c[20000001];
char ch[20],a[20];

int C(char x)
{
	
	if(x=='A') return 1;
	if(x=='C') return 2;
	if(x=='G') return 3;
	return 4;
}

int search(int k, int x, int y, int t)
{
	if(k==strlen(a))
	{
		if(!t) c[x] = 1;
		return c[x];
	}
	return search(k+1,x+C(a[k])*y,y*4,t);
}

int main()
{
	int n;
	scanf("%d",&n);
	while(n--)
	{
		scanf("%s %s",ch,a);
		if(ch[0]=='i') 
		{
			search(0,0,1,0);
		}
		else
		{
			if(search(0,0,1,1))
			{
				printf("yes\n");
			}
			else printf("no\n");
		}
	}
	return 0;
}
	
