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Count Dice Sequences

Count ordered die-roll sequences with a given total.

Problem

A standard die produces an integer from 1 through 6. Count all nonempty ordered sequences of outcomes whose sum is target. Different orders count separately. Return the count modulo 1,000,000,007.

Implement dice_combinations(target).

Input

target: The required sum of all rolls.

Output

Return the number of sequences modulo 1,000,000,007.

Constraints

1 ≤ target ≤ 1,000,000. Taking a count modulo 1,000,000,007 means returning its remainder after division by that number.

Examples

Example 1
Input:
target = 2

Expected output:
expected = 2
Input:
long long target = 2;

Expected output:
long long expected = 2;
Input:
long target = 2;

Expected output:
long expected = 2;

Explanation

The two sequences are [2] and [1, 1].

Example 2
Input:
target = 4

Expected output:
expected = 8
Input:
long long target = 4;

Expected output:
long long expected = 8;
Input:
long target = 4;

Expected output:
long expected = 8;

Explanation

The sequences are [4], [1,3], [3,1], [2,2], [1,1,2], [1,2,1], [2,1,1], and [1,1,1,1].

References

This challenge is adapted for CodeUtility. Follow the statement and constraints above.

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