Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin, setrecursionlimit
from heapq import heappop, heapify
input = stdin.readline
def Is(): return map(int, input().split())
def LI(): return list(map(int, input().split()))


n, m = Is()
A = LI()
tmp = 0
for i in range(m):
    b, c = Is()
    A += [c]*b
    tmp += b
heapify(A)

for i in range(tmp):
    heappop(A)

print(sum(A))


Fixed submission:
from collections import defaultdict, deque, Counter
from heapq import heappush, heappop, heapify
from itertools import permutations, accumulate, combinations, combinations_with_replacement
from math import sqrt, ceil, floor, factorial
from bisect import bisect_left, bisect_right, insort_left, insort_right
from copy import deepcopy
from operator import itemgetter
from functools import reduce
from fractions import gcd
import sys
def I(): return int(input())
def Is(): return map(int, input().split())
def LI(): return list(map(int, input().split()))
def TI(): return tuple(map(int, input().split()))
def IR(n): return [I() for _ in range(n)]
def LIR(n): return [LI() for _ in range(n)]
def TIR(n): return [TI() for _ in range(n)]
def S(): return input()
def Ss(): return input().split()
def LS(): return list(input())
def SR(n): return [S() for _ in range(n)]
def SsR(n): return [Ss() for _ in range(n)]
def LSR(n): return [LS() for _ in range(n)]
sys.setrecursionlimit(10**6)
MOD = 10**9+7
INF = float('inf')


n, m = Is()
A = LI()
BC = TIR(m)
A.sort()
BC.sort(key=itemgetter(1), reverse=True)
D = []
for b, c in BC:
    D += [c]*b
    if len(D) > n:
        break

for i in range(min(n, len(D))):
    if A[i] < D[i]:
        A[i] = D[i]
    else:
        break

print(sum(A))

Buggy python submission (verdict: Time Limit Exceeded):
from collections import defaultdict, deque, Counter
from heapq import heappush, heappop, heapify
from itertools import permutations, accumulate, combinations, combinations_with_replacement
from math import sqrt, ceil, floor, factorial
from bisect import bisect_left, bisect_right, insort_left, insort_right
from copy import deepcopy
from operator import itemgetter
from functools import reduce
from fractions import gcd
import sys
def I(): return int(input())
def Is(): return map(int, input().split())
def LI(): return list(map(int, input().split()))
def TI(): return tuple(map(int, input().split()))
def IR(n): return [I() for _ in range(n)]
def LIR(n): return [LI() for _ in range(n)]
def TIR(n): return [TI() for _ in range(n)]
def S(): return input()
def Ss(): return input().split()
def LS(): return list(input())
def SR(n): return [S() for _ in range(n)]
def SsR(n): return [Ss() for _ in range(n)]
def LSR(n): return [LS() for _ in range(n)]
sys.setrecursionlimit(10**6)
MOD = 10**9+7
INF = float('inf')


n, m = Is()
A = LI()
tmp = 0
for i in range(m):
    b, c = Is()
    A += [c]*b
    tmp += b
heapify(A)

for i in range(tmp):
    heappop(A)

print(sum(A))


Fixed submission:
from collections import defaultdict, deque, Counter
from heapq import heappush, heappop, heapify
from itertools import permutations, accumulate, combinations, combinations_with_replacement
from math import sqrt, ceil, floor, factorial
from bisect import bisect_left, bisect_right, insort_left, insort_right
from copy import deepcopy
from operator import itemgetter
from functools import reduce
from fractions import gcd
import sys
def I(): return int(input())
def Is(): return map(int, input().split())
def LI(): return list(map(int, input().split()))
def TI(): return tuple(map(int, input().split()))
def IR(n): return [I() for _ in range(n)]
def LIR(n): return [LI() for _ in range(n)]
def TIR(n): return [TI() for _ in range(n)]
def S(): return input()
def Ss(): return input().split()
def LS(): return list(input())
def SR(n): return [S() for _ in range(n)]
def SsR(n): return [Ss() for _ in range(n)]
def LSR(n): return [LS() for _ in range(n)]
sys.setrecursionlimit(10**6)
MOD = 10**9+7
INF = float('inf')


n, m = Is()
A = LI()
BC = TIR(m)
A.sort()
BC.sort(key=itemgetter(1), reverse=True)
D = []
for b, c in BC:
    D += [c]*b
    if len(D) > n:
        break

for i in range(min(n, len(D))):
    if A[i] < D[i]:
        A[i] = D[i]
    else:
        break

print(sum(A))