MathDB
to be even or to be odd,this is the matter :D

Source: JBMO 1997, Problem 5

June 11, 2004

Problem Statement

Let n1n_1, n2n_2, …\ldots, n1998n_{1998} be positive integers such that n12+n22+⋯+n19972=n19982. n_1^2 + n_2^2 + \cdots + n_{1997}^2 = n_{1998}^2. Show that at least two of the numbers are even.
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