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())
dic = {}

for a in range(len(A)):
  if A[a] not in dic:
    dic[ A[a] ] = 1
  else:
    dic[ A[a] ] += 1

for a in range(M):
  B,C = map(int,raw_input().split())
  if C not in dic:
    dic[C] = B
  else:
    dic[C] += B

dic_list = sorted(dic.items(), key=lambda x:x[0], reverse=True)
ans = 0
now = 0
for a in range( len(dic_list) ):
  if dic_list[a][1] + now >= N:
    ans += dic_list[a][0] * (N-now)
    break
  ans += dic_list[a][0] * dic_list[a][1]
  now += dic_list[a][1]

print ans
