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 solve():
    N, M = [int(_) for _ in raw_input().split()]
    A = [int(_) for _ in raw_input().split()]
    A.sort(reverse = True)
    BC = []
    for i in range(M):
        Bi, Ci = [int(_) for _ in raw_input().split()]
        BC.append([Bi, Ci])
    BC.sort(key = lambda x: x[1], reverse = True)
    ind_BC = 0
    ind_A = 0
    merged = []
    while ind_A < N and ind_BC < M:
        Bi = BC[ind_BC][0]
        Ci = BC[ind_BC][1]
        if A[ind_A] > Ci:
            merged.append(A[ind_A])
            ind_A += 1
        else:
            merged.extend([Ci] * Bi)
            ind_BC += 1
        if len(merged) >= N:
            break
    if len(merged) < N:
        if ind_A < N:
            merged.extend(A[ind_A:])
        elif ind_BC < M:
            for i in range(ind_BC, M):
                Bi = BC[ind_BC][0]
                Ci = BC[ind_BC][1]
                merged.extend([Bi] * Ci)
                if len(merged) >= N:
                    break
    merged = merged[:N]
    print sum(merged)

if __name__ == '__main__':
    solve()
