program-id.y.data division.working-storage section.
1 m pic 9(9).
1 n pic 9(9).
1 s pic x(9).
procedure division.a.accept s
unstring s delimited" "into m n
compute n=(1+n+m^2/n)/2
display n(9- function log10(n):)if n<>1645 go a.