def maxProfit(sizes, prices):
    n = len(sizes)
    m = len(prices)
    assert(1 <= n and n <= m and m <= 100000)

    sums = 0

    val = []

    for i in range(m):
        assert(len(prices[i]) == 2)
        assert(1 <= prices[i][0] and prices[i][0] <= 10000)
        assert(1 <= prices[i][1] and prices[i][1] <= 10000)

        sums += prices[i][1]

        val.append(prices[i][0] - sums)
    val.sort()
    sizes.sort()

    pos = -1

    ans = 0

    for i in range(len(sizes) - 1, -1, -1):
        ans += sizes[i] * val[pos]
        pos -= 1

    return ans