def bin_search(arr, x):
    l, r = -1, len(arr)
    while r - l > 1:
        m = (l + r) // 2
        if arr[m] > x:
            r = m
        else:
            l = m
    return r
default = (0, 10000) # summ, price
def f(x, y):
    xs, xp = x
    ys, yp = y
    if xs + ys - yp  > xs - xp:
        return xs + ys, yp
    else:
        return x
def update(tree, ind, value):
    if ind < 1: return
    tree[ind] = value
    if ind % 2 == 0:
        update(tree, ind // 2, f(value, tree[ind + 1]))
    else:
        update(tree, ind // 2, f(tree[ind - 1], value))
def init(l):
    from math import log2, ceil
    size = 2 ** ceil(log2(l))
    tree = [default] * (size * 2)
    return tree

attack_count, shield_count, monsters_count = map(int, input().split())
attack = [list(map(int, input().split())) for _ in range(attack_count)]
shield = [list(map(int, input().split())) for _ in range(shield_count)]
monsters = [list(map(int, input().split())) for _ in range(monsters_count)]  # shield, attack, reward
MAX = 0
monsters.sort()
cur_monsters = []
m = 0
tree = init(len(shield))
tsize = len(tree) // 2
shield.sort()
shieldes = [s[0] for s in shield]
for i in range(len(shield)):
    update(tree, tsize + i, (0, shield[i][1]))
for a, pr in attack:
    while m < len(monsters) and a > monsters[m][0]:
        monster = monsters[m]
        ind = bin_search(shieldes, monster[1])
        if ind < len(shield):
            update(tree, tsize+ind, (tree[tsize + ind][0] + monster[2], shield[ind][1]))
        m += 1
        print(f'{tree=} {a=} {pr=} {monster=}')
    m_def = tree[1][0] - tree[1][1]
    MAX = max(m_def - pr, MAX)
print(MAX)