- Time limit: 1.00 s
- Memory limit: 512 MB
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.
Print one integer: the maximum number of coins you can collect.
- $1 \le n \le 10^5$
- $1 \le m \le 2 \cdot 10^5$
- $1 \le k_i \le 10^9$
- $1 \le a,b \le n$
4 5 2 7