Let's denote *d*(*n*) as the number of divisors of a positive integer *n*. You are given three integers *a*, *b* and *c*. Your task is to calculate the following sum:

Find the sum modulo 1073741824 (2<sup class="upper-index">30</sup>).
The first line contains three space-separated integers *a*, *b* and *c* (1 ≤ *a*, *b*, *c* ≤ 100).
a, b, c = map(int, input().split())
MOD = 1073741824  


dp = [[[0] * (c + 1) for _ in range(b + 1)] for _ in range(a + 1)]


for x in range(1, a + 1):
    for y in range(1, b + 1):
        for z in range(1, c + 1):
            product = x * y * z
            for i in range(1, product + 1):
                if product % i == 0:
                    dp[x][y][z] += 1


total_sum = 0
for x in range(1, a + 1):
    for y in range(1, b + 1):
        for z in range(1, c + 1):
            total_sum += dp[x][y][z]


print(total_sum % MOD)

   						 		 			         	 				