√m=√1998-√n
m=1998+n-2√1998n
1998n=p^2,
1998=2x3^3x37
n=2x3x37q^2=222q^2,p=2x9x37q=666q
m=1998+222q^2-2x666q=222(9+q^2-6q)=222(q-3)^2
n