You have N cards. On the i-th card, an integer A_i is written.
For each j = 1, 2, ..., M in this order, you will perform the following operation once:
Operation: Choose at most B_j cards (possibly zero). Replace the integer written on each chosen card with C_j.
Find the maximum possible sum of the integers written on the N cards after the M operations.

-----Constraints-----
- All values in input are integers.
- $1 \leq N \leq 10^5$
- $1 \leq M \leq 10^5$
- $1 \leq A_i, C_i \leq 10^9$
- $1 \leq B_i \leq N$

-----Input-----
Input is given from Standard Input in the following format:
N M
A_1 A_2 ... A_N
B_1 C_1
B_2 C_2
$\vdots$
B_M C_M

-----Output-----
Print the maximum possible sum of the integers written on the N cards after the M operations.

-----Sample Input-----
3 2
5 1 4
2 3
1 5

-----Sample Output-----
14

By replacing the integer on the second card with 5, the sum of the integers written on the three cards becomes 5 + 5 + 4 = 14, which is the maximum result.

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