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

def main():
    n, m = map(int, raw_input().split())
    aa = map(int, raw_input().split())
    cb = [[a, 1] for a in aa]
    for _ in range(m):
        b, c = map(int, raw_input().split())
        cb.append([c, b])
    cb.sort(reverse=True)
    s = 0
    count = 0
    for c, b in cb:
        if count + b < n:
            s += b * c
        else:
            b = n - count
            s += b * c
        count += b
        if count >= n:
            break
    print s


if __name__ == '__main__':
    main()
