#!/usr/bin/python3

# Přečte řádek čísel
def intline():
    i = input()
    l = list(map(int, i.split()))
    return l

M, N, Q = intline()
X = sorted(intline())
Y = sorted(intline())
best = 0

for x in X:
    l, r = 0, N - 1
    while l <= r:
        c = (l + r) // 2
        if x * Y[c] <= Q:
            best = max(best, x * Y[c])
            l = c + 1
        else:
            r = c - 1

print(best)