Angel Relief

K: Relief (Angel Relief)

Tenma, an angel, decides to save a city.

The city has a rectangular shape divided into north-south $H$ parcels x east-west $W$ parcels, with houses in each parcel.

The $X$ th section from the north and the $Y$ th section from the west are represented by $(X, Y)$.

The house in parcel $(i, j)$ is inhabited by $A_ {i, j}$ people.

Tenshin chooses a rectangular area whose sides are parallel or vertical to north-south or east-west, and rescues all the people living in it one by one.

Tenshin does this for every possible rectangle.

Find the total number of times Tenma-san rescues people.

input

The integers $H, W$ are given on the first line, separated by blanks.

Of the following $H$ lines, the integers $ A_ {i, 1}, A_ {i, 2}, A_ {i, 3}, \ dots, A_ {i, W} $ are blank on the $i$ line. Given as a delimiter.

output

Output the total number of times Tenma-san rescues people.

Constraint

• $H, W$ are integers between $1$ and $500$
• $A_ {i, j}$ are all integers greater than or equal to $1$ and less than or equal to $9$.

Input example 1

twenty two 1 2 4 8

Output example 1

60

For example, if you choose a rectangular area with $(1, 1)$ in the upper left and $(2, 2)$ in the lower right, you will rescue $15$ people there one by one, so a total of $15$ times. Relief.

$1, 2, 3, 4, 5, 8, 10, 12, 15$ relief for each of the $9$ rectangular areas, for a total of $60$.

Input example 2

twenty three one two Three 4 5 6

Output example 2

140

Example

Input

2 2 1 2 4 8

Output

60

inputFormat

input

The integers $H, W$ are given on the first line, separated by blanks.

Of the following $H$ lines, the integers $ A_ {i, 1}, A_ {i, 2}, A_ {i, 3}, \ dots, A_ {i, W} $ are blank on the $i$ line. Given as a delimiter.

outputFormat

output

Output the total number of times Tenma-san rescues people.

Constraint

• $H, W$ are integers between $1$ and $500$
• $A_ {i, j}$ are all integers greater than or equal to $1$ and less than or equal to $9$.

Input example 1

twenty two 1 2 4 8

Output example 1

60

For example, if you choose a rectangular area with $(1, 1)$ in the upper left and $(2, 2)$ in the lower right, you will rescue $15$ people there one by one, so a total of $15$ times. Relief.

$1, 2, 3, 4, 5, 8, 10, 12, 15$ relief for each of the $9$ rectangular areas, for a total of $60$.

Input example 2

twenty three one two Three 4 5 6

Output example 2

140

Example

Input

2 2 1 2 4 8

Output

60

样例

2 2
1 2
4 8

60