a and b are numbers among the 27 natural numbers from 1 to 27. If the product of a and b is a multiple of 100, then we call (a, b) a "hopeful number pair". Only when a=b, (a, b) and (b, a) are the same number pair, so how many "hope number pairs" are there in 1-27?
a、b是1～27这27个自然数中的数，如果a与b的乘积是100的倍数，那么我们称(a，b)为"希望数对"．只有在a=b时，(a，b)与(b，a)才是同一个数对，那么1～27中一共有多少个"希望数对"．
<result>9</result>