p=2a^2-8ab+17b^2-16a-4b+2059
=(a-4b)^2+(a-8)^2+(b-2)^2+2059-64-4
=(a-4b)^2+(a-8)^2+(b-2)^2+1991
p=0+0+0+1991
=1991
a=4b
b=2
a=8