int main(int argc, char* argv[])
{
	int n,m=0;
	char a[39];
    int i,j,p;
	scanf("%d",&n);
	for (i=0;i<n;i++)
	{
		m=0;
		scanf("%s",a);
		for (j=0;a[j]!='\0';j++)
		{
			if(((a[j]>='0')&&(a[j]<='9')&&(j>0))||((a[j]>='A')&&(a[j]<='Z'))||((a[j]>='a')&&(a[j]<='z'))||(a[j]=='_'))
				m++;
		}
		p=strlen(a);
		if((m==p)&&((a[0]>='A'&&a[0]<='Z')||(a[0]>='a'&&a[0]<='z')||(a[0]=='_')))
			printf("yes\n");
		else 
			printf("no\n");			
	}
	return 0;
}
