CF75A.Life Without Zeros

Can you imagine our life if we removed all zeros from it? For sure we will have many problems.

In this problem we will have a simple example if we removed all zeros from our life, it's the addition operation. Let's assume you are given this equation a + b = c, where a and b are positive integers, and c is the sum of a and b. Now let's remove all zeros from this equation. Will the equation remain correct after removing all zeros?

For example if the equation is 101 + 102 = 203, if we removed all zeros it will be 11 + 12 = 23 which is still a correct equation.

But if the equation is 105 + 106 = 211, if we removed all zeros it will be 15 + 16 = 211 which is not a correct equation.

试想一下，如果我们从生活中去掉所有的数字 0，生活会变成什么样？毫无疑问，我们将面临诸多问题。

本题将给出一个简单的例子：如果从我们的生活中去掉所有数字 0，那么加法运算会发生什么变化。假设你被给定如下等式：$a + b = c$，其中 $a$ 和 $b$ 是正整数，$c$ 是 $a$ 与 $b$ 的和。现在，让我们从该等式中去掉所有的数字 0。去掉所有 0 后，该等式是否仍然成立？

例如，若原等式为 $101 + 102 = 203$，去掉所有 0 后变为 $11 + 12 = 23$，这仍然是一个正确的等式。

但若原等式为 $105 + 106 = 211$，去掉所有 0 后变为 $15 + 16 = 211$，这就不再是一个正确的等式了。

The input will consist of two lines, the first line will contain the integer a, and the second line will contain the integer b which are in the equation as described above (1 ≤ a, b ≤ 109). There won't be any leading zeros in both. The value of c should be calculated as c = a + b.

输入包含两行，第一行包含整数 $a$，第二行包含整数 $b$，它们即为上述方程中的参数（$1 \le a,\,b \le 10^9$）。$a$ 和 $b$ 均不含前导零。需按 $c = a + b$ 计算 $c$ 的值。

The output will be just one line, you should print "YES" if the equation will remain correct after removing all zeros, and print "NO" otherwise.

输出仅一行，如果移除所有数字 0 后等式仍然成立，则输出 “YES”，否则输出 “NO”。