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
l = raw_input().split()
N = int(l[0])
M = int(l[1])

BC = []

l = raw_input().split()
A = [int(x) for x in l]

for i in range(M):
    l = raw_input().split()
    bc = [int(l[0]), int(l[1])]
    BC.append(bc)

A.sort()
BC.sort(key = lambda x: -x[1])
# print(N, M, A, BC)

i0 = 0
i1 = 0
for i in range(N):
    # print(BC[i0])
    b = BC[i0][0]
    c = BC[i0][1]

    if A[i] < c:
        A[i] = c
        i1 += 1
    if i1 == b:
        i0 += 1
        i1 = 0
    # print(A)
    if i0 == M:
        break

# print(A)
print(sum(A))
