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
#include <iostream>
using namespace std;
long long w, h, n, d[30], it, wynik;
void policz(long long a, long long b){
    if(b==0) return;
    long long x=a/d[it], y=b/d[it];
    wynik+=x*y;
    if(x==0 or y==0){
        it--;
        policz(a, b);
        return;
    }
    long long a1 = a%d[it], b1 = y*d[it];
    for(int i=it-1; i>=0 and a1>0; i--){
        x=a1/d[i];
        wynik+=x*b1/d[i];
        a1=a1%d[i];
    }
    it--;
    policz(a, b%d[it+1]);

}
int main(){
    cin>>w>>h>>n;
    for(int i=0; i<n; i++) cin>>d[i];
    if(w%d[0]>0 or h%d[0]>0){
        cout<<"-1";
        return 0;
    }
    it=n-1;
    while(w<d[it] or h<d[it]) it--;
    policz(w, h);
    cout<<wynik;

}