Rating changes for last rounds are temporarily rolled back. They will be returned soon.
×

Codeforces Round 428 (Div. 2) |
---|

Finished |

Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

brute force

greedy

implementation

*1900

No tag edit access

The problem statement has recently been changed. View the changes.

×
B. Game of the Rows

time limit per test

1 secondmemory limit per test

256 megabytesinput

standard inputoutput

standard outputDaenerys Targaryen has an army consisting of *k* groups of soldiers, the *i*-th group contains *a*_{i} soldiers. She wants to bring her army to the other side of the sea to get the Iron Throne. She has recently bought an airplane to carry her army through the sea. The airplane has *n* rows, each of them has 8 seats. We call two seats neighbor, if they are in the same row and in seats {1, 2}, {3, 4}, {4, 5}, {5, 6} or {7, 8}.

Daenerys Targaryen wants to place her army in the plane so that there are no two soldiers from different groups sitting on neighboring seats.

Your task is to determine if there is a possible arranging of her army in the airplane such that the condition above is satisfied.

Input

The first line contains two integers *n* and *k* (1 ≤ *n* ≤ 10000, 1 ≤ *k* ≤ 100) — the number of rows and the number of groups of soldiers, respectively.

The second line contains *k* integers *a*_{1}, *a*_{2}, *a*_{3}, ..., *a*_{k} (1 ≤ *a*_{i} ≤ 10000), where *a*_{i} denotes the number of soldiers in the *i*-th group.

It is guaranteed that *a*_{1} + *a*_{2} + ... + *a*_{k} ≤ 8·*n*.

Output

If we can place the soldiers in the airplane print "YES" (without quotes). Otherwise print "NO" (without quotes).

You can choose the case (lower or upper) for each letter arbitrary.

Examples

Input

2 2

5 8

Output

YES

Input

1 2

7 1

Output

NO

Input

1 2

4 4

Output

YES

Input

1 4

2 2 1 2

Output

YES

Note

In the first sample, Daenerys can place the soldiers like in the figure below:

In the second sample, there is no way to place the soldiers in the plane since the second group soldier will always have a seat neighboring to someone from the first group.

In the third example Daenerys can place the first group on seats (1, 2, 7, 8), and the second group an all the remaining seats.

In the fourth example she can place the first two groups on seats (1, 2) and (7, 8), the third group on seats (3), and the fourth group on seats (5, 6).

Codeforces (c) Copyright 2010-2024 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Apr/22/2024 19:42:21 (h2).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|