D - Integer Cards

Score : $400$ points

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.

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.

3 2
5 1 4
2 3
1 5

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.

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

338

3 2
100 100 100
3 99
3 99

300

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

10000000001

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