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
n, m = map(int, raw_input().split())
A = map(int, raw_input().split())
BC = []
A.sort()
for i in range(m):
    b, c = map(int, raw_input().split())
    BC.append((b, c))
BC.sort(key=lambda x : x[1], reverse=True)
def binary_search(val, lo, hi):
    if hi < lo:
        return -1
    mid = (lo + hi) / 2
    if A[mid] <= val and mid + 1 >= len(A):
        return mid
    elif A[mid] <= val and A[mid+1] > val:
        return mid
    elif A[mid] <= val:
        return binary_search(val, mid+1, hi)
    elif A[mid] > val:
        return binary_search(val, lo, mid-1)

boundery = 0
left = []
for b, c in BC:
    lte_index = binary_search(c, 0, len(A)-1)
    if lte_index < boundery:
        continue
    if lte_index + 1 > boundery + b:
        number = b
    else:
        number = lte_index - boundery + 1
    left.append((c, number))
    boundery = boundery + number
    if boundery >= n:
        break
total = 0
num_of_elements = 0
for i in range(len(left)):
    c, num = left[i]
    total += c * num
    num_of_elements += num
for i in range(num_of_elements, n):
    total += A[i]
print total

