#include <bits/stdc++.h>
using namespace std;
long long mp[(int)1e6 + 6];
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long ans = 0, mod = 1073741824;
  for (int i = 1; i <= a; i++) {
    for (int j = 1; j <= b; j++) {
      for (int k = 1; k <= c; k++) {
        long long temp = i * j * k;
        if (!mp[temp]) {
          long long cnt = 0;
          for (int l = 1; l * l <= temp; l++) {
            if (temp % l == 0) {
              cnt++;
              if (temp / l != l) cnt++;
            }
          }
          mp[temp] = cnt;
        }
        ans += (mp[temp]) % mod;
      }
    }
  }
  cout << ans;
  return 0;
}

### Prompt

Develop a solution in cpp to the problem described below:

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:

<image>

Find the sum modulo 1073741824 (230).

Input

The first line contains three space-separated integers a, b and c (1 ≤ a, b, c ≤ 2000).

Output

Print a single integer — the required sum modulo 1073741824 (230).

Examples

Input

2 2 2


Output

20


Input

4 4 4


Output

328


Input

10 10 10


Output

11536

Note

For the first example.

  * d(1·1·1) = d(1) = 1; 
  * d(1·1·2) = d(2) = 2; 
  * d(1·2·1) = d(2) = 2; 
  * d(1·2·2) = d(4) = 3; 
  * d(2·1·1) = d(2) = 2; 
  * d(2·1·2) = d(4) = 3; 
  * d(2·2·1) = d(4) = 3; 
  * d(2·2·2) = d(8) = 4. 



So the result is 1 + 2 + 2 + 3 + 2 + 3 + 3 + 4 = 20.

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
long long mp[(int)1e6 + 6];
int main() {
  long long a, b, c;
  cin >> a >> b >> c;
  long long ans = 0, mod = 1073741824;
  for (int i = 1; i <= a; i++) {
    for (int j = 1; j <= b; j++) {
      for (int k = 1; k <= c; k++) {
        long long temp = i * j * k;
        if (!mp[temp]) {
          long long cnt = 0;
          for (int l = 1; l * l <= temp; l++) {
            if (temp % l == 0) {
              cnt++;
              if (temp / l != l) cnt++;
            }
          }
          mp[temp] = cnt;
        }
        ans += (mp[temp]) % mod;
      }
    }
  }
  cout << ans;
  return 0;
}

```