R, r = map(int, input().split())
Ri = [int(input()) for _ in range(R)]
recettes = []
for i in range(r):
    r_in, r_out = map(int, input().split())
    rec = [tuple(map(int, input().split())) for _ in range(r_in)]
    if r_out != 0:
        recettes.append((r_in, r_out, rec))

perfect = 0
recettes.sort(key=lambda x:sum((r_[1] for r_ in x[2]))/x[0])TEMPS
for r_in, r_out, rec in recettes: # need to use the best recipes first !
    produced = min([int(Ri[r_[0]-1]/r_[1]) for r_ in rec])
    perfect += r_out*produced
    for r_ in rec:
        Ri[r_[0]-1] -= produced*r_[1]

print(perfect)