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.

Examples

Input

3 2
5 1 4
2 3
1 5


Output

14


Input

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


Output

338


Input

3 2
100 100 100
3 99
3 99


Output

300


Input

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


Output

10000000001
import sys
from pprint import pprint

def solve(n, m, a, ops):
    a.sort()
    ops.sort(reverse=True)
    # pprint(a)
    # pprint(ops)
    start = 0
    for ope, count in ops:
        i = 0
        for a_i in xrange(start, start+count):
            if a_i >= n:
                break
            if a[a_i] < ope and count > 0:
                count -= 1
                # print a_i, '=>', ope, ' count:', count
                a[a_i] = ope
                i += 1
            else:
                break
        start += i

    print sum(a)

if __name__ == '__main__':

    ops = []
    n, m = map(int, sys.stdin.readline().strip().split(" "))
    a = map(int, sys.stdin.readline().strip().split(" "))
    for _ in range(m):
        b, c = map(int, sys.stdin.readline().strip().split(" "))
        ops.append((c, b))

    solve(n, m, a, ops)