简单枚举：
{
Author:wzx961008
Problem:POJ 1183-arctan
Verdict:Accepted
Language:PASCAL
Run Time:0.032s
AC Date:2011-4-19
}
var a,b,c,k,ans,tmp:qword;
i:longint;
begin
readln(a); ans:=maxlongint;
for i:=1 to a do begin
k:=a*(a+i)+1; tmp:=k div i+a+i;
if (k mod i=0)and(tmp<ans) then ans:=tmp;
end;
writeln(ans);
end.
