20 20
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 10 4
0 1 4 2 7 0 10 0 5 8
 10 7
10 8 6 5 0 0 0 4 3 9
 10 1
8 7 0 2 0 10 0 0 3 5
 10 7
7 9 2 10 0 0 0 3 5 1
 10 2
10 0 9 0 0 4 2 6 8 0
 10 2
0 7 0 10 8 0 4 2 3 0

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
 3
4
8
9
 1
5
6
10
 2
4
5
7
8
10
 1
2
6
7
 1
2
3
4
6
7
8
9
 4
5
6
7
8

#include <bits/stdc++.h>
using namespace std;
const int big = 2000000000;
const double INF = 1e9;
const double EPS = 1e-9;
int main() {
  int n;
  long long p, q, r, a;
  bool o = true;
  scanf("%I64d%I64d%d", &p, &q, &n);
  for (int x = 0, _c = n; x < _c; ++x) {
    scanf("%I64d", &a);
    if (q == 0) {
      o = false;
      break;
    }
    r = (p / q) - a;
    p %= q;
    if (r < 0) {
      o = false;
      break;
    }
    p += (r * q);
    swap(p, q);
  }
  if (o && r == 0LL && q == 0LL)
    printf("YES\n");
  else
    printf("NO\n");
  return 0;
}
