Problem Statement

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.

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.

Constraints

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

Sample Input 1

3 2
5 1 4
2 3
1 5

Sample Output 1

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.

Sample Input 2

10 3
1 8 5 7 100 4 52 33 13 5
3 10
4 30
1 4

Sample Output 2

338

Sample Input 3

3 2
100 100 100
3 99
3 99

Sample Output 3

300

Sample Input 4

11 3
1 1 1 1 1 1 1 1 1 1 1
3 1000000000
4 1000000000
3 1000000000

Sample Output 4

10000000001

The output may not fit into a 32-bit integer type.

见题面 Input 部分

见题面 Output 部分