1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair <int, int>;
using pll = pair <ll, ll>;
const int inf = 1e9+7;
const ll inf_ll = 1e18+7;

void boost ()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
}

ll h, w, n, d[37];

ll policz(ll h, ll w, ll n) {
    if (h == 0 || w == 0)
        return 0;

    while (n >= 1 && (d[n] > h || d[n] > w))
        n--;

    if (n == 0)
        return -1;

    ll x = h / d[n];
    ll xr = h - (x * d[n]);
    ll y = w / d[n];
    ll yr = w - (y * d[n]);

    ll s1 = policz(xr, yr, n);
    ll s2 = policz(xr, w - yr, n);
    ll s3 = policz(h - xr, yr, n);
    if (s1 == -1 || s2 == -1 || s3 == -1)
        return -1;
    return x * y + s1 + s2 + s3;
}

int main ()
{
    boost();

    cin >> h >> w;
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> d[i];
    }

    cout << policz(h, w, n) << "\n";

    return 0;
}