输入描述:

The first line contains two space-separated integers p, q(1 ≤ q ≤ p ≤ 1018) — the numerator and the denominator of the first fraction.The second line contains integer n(1 ≤ n ≤ 90) — the height of the second fraction. The third line contains n space-separated integers a1, a2, ..., an(1 ≤ ai ≤ 1018) — the continued fraction.Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.

输出描述:

Print "YES" if these fractions are equal and "NO" otherwise.

9 4<br />2<br />2 4<br />9 4<br />3<br />2 3 1<br />9 4<br />3<br />1 2 4<br />

YES<br />YES<br />NO<br />

备注:

In the first sample .In the second sample .In the third sample .