# Problem E

Mirror Strings

A character is called a “mirror character” if it looks the
same when flipped up and down, and the same when flipped left
and right. The uppercase mirror characters, `H`, `I`, `O`, `X`. The lowercase
mirror characters are `l` (since people
often write this as a vertical line), `o`, and `x`.

In the same way, a string that looks the same when flipped
up and down or when flipped left and right is called a “mirror
string”. For example, `XXOOOOXX` is a
mirror string.

The height of the character affects the construction of the
mirror string. For example, `llll` and
`oooo` are both mirror strings.
However, `lool` is not a mirror string
because it looks different when it is flipped up and down. The
uppercase characters `H`, `I`, `O`, `X` and the lowercase character `l` are both of height $2$ while the lowercase letters
`x` and `o` are
of height 1.

Tommy wants to construct mirror strings with lower characters and upper characters. He wants to know how many different mirror strings have length in the range $[L, R]$ (i.e. how many mirror strings have a length $m$ satisfying $L \leq m \leq R$).

For example, the $7$
mirror strings of length $1$ are `H`,
`I`, `O`,
`X`, `l`,
`o`, or `x`.
There are also $7$ mirror
strings of length $2$,
namely `HH`, `II`, `OO`, `XX`, `ll`, `oo`, and `xx`. But there
are many more mirror strings of bigger lengths, for example
there are $29$ mirror
strings of length $3$.

## Input

The first and only line of input contains two integers $L$ and $R$ ($1 \leq L \leq R \leq 10^6$), indicating the range of the lengths of mirror strings that Tommy wants to count.

## Output

Output the number of mirror strings that have a length $m$ satisfing $L \leq m \leq R$. Since there can be many such strings, you should output the answer modulo $10^9 + 7$ (i.e. the remainder of the answer when it is divided by $10^9 + 7$).

Sample Input 1 | Sample Output 1 |
---|---|

1 4 |
72 |

Sample Input 2 | Sample Output 2 |
---|---|

2 3 |
36 |

Sample Input 3 | Sample Output 3 |
---|---|

2 1000000 |
664868576 |