int main()
{
	char m[100][20];
	int b=0,n,i,j;
	scanf("%d",&n);

	for(i=0;i<n;i++)
	scanf("%s",m[i]);

	for(i=0;i<n;i++)
	{for(j=0;j<strlen(m[i]);j++)
	{if(m[i][j]>'z'||m[i][j]<48) 
	{b++;
	break;}
	else if(m[i][j]>57&&m[i][j]<'A')
	{b++;
	break;}
	else if(m[i][j]>'Z'&&m[i][j]<'a'&&m[i][j]!='_')
	{b++;
	break;}
	else if(m[i][0]>=48&&m[i][0]<=57)
	{b++;
	break;}
	}
	if(b==0)
	{printf("yes\n");
	continue;}
	else
	{printf("no\n");
	b=0;
     continue;
	}
	}
return 0;
}




