if k=8 and m=4, then the 2-height of k is 3, and the 2-height of m is 2. if k=6 and m=4, then the 2-height of k is 2, the same as the m's hence, (1) is insufficient. if k/m is an even integer, supposing that k=m*2t, then suppose that the 2-height of m is n, that means 2^n is the factor of m and m can be represented as 2^n*s. we have assumed that k=m*2t, so k=2^n*s*2*t=2^(n+1)*s*t thus, the 2-height of k is (n+1) |