**Time limit:**1.00 s**Memory limit:**512 MB

**Input**

The first input line has two integers $n$ and $m$: the number of rooms and tunnels. The rooms are numbered $1,2,\dots,n$.

Then, there are $n$ integers $k_1,k_2,\ldots,k_n$: the number of coins in each room.

Finally, there are $m$ lines describing the tunnels. Each line has two integers $a$ and $b$: there is a tunnel from room $a$ to room $b$. Each tunnel is a one-way tunnel.

**Output**

Print one integer: the maximum number of coins you can collect.

**Constraints**

- $1 \le n \le 10^5$

- $1 \le m \le 2 \cdot 10^5$

- $1 \le k_i \le 10^9$

- $1 \le a,b \le n$

**Example**

Input:

`4 4`

4 5 2 7

1 2

2 1

1 3

2 4

Output:

`16`