<Table> <Tr> <Td> </Td> </Tr> <Tr> <Td> Jimmy Carter (age 93) since 1981 </Td> </Tr> </Table> <Tr> <Td> Jimmy Carter (age 93) since 1981 </Td> </Tr> <Table> <Tr> <Td> </Td> </Tr> <Tr> <Td> George H.W. Bush (age 93) since 1993 </Td> </Tr> </Table> <Tr> <Td> George H.W. Bush (age 93) since 1993 </Td> </Tr>

What does the president of the us do