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
import heapq
range = xrange
input = raw_input

n,m = [int(x) for x in input().split()]

A = [(int(x),1) for x in input().split()]

# Keep track of number of elements in A and the sum of all the elements
Acount = n
Asum = sum(a[0]*a[1] for a in A)

heapq.heapify(A)
for _ in range(m):
    new_count,new_val = [int(x) for x in input().split()]
    new_pair = (new_val,new_count)
    
    # Try to add this new pair to A
    heapq.heappush(A, new_pair)
    Acount += new_count
    Asum += new_count * new_val

    # While there are too many elements in A
    while Acount>n:
        # Remove the ones with the smallest values
        old_pair = heapq.heappop(A)
        
        old_count = old_pair[1]
        old_val = old_pair[0]
        Acount -= old_count
        Asum -= old_count * old_val

        # If there are too few elements left in A, then add back
        # some of the elements in the old pair
        if Acount<n:
            count = min(n - Acount, old_count)
            
            heapq.heappush(A, (old_val, count))
            Acount += count
            Asum += count * old_val

    # print Asum
print Asum