program a1;
uses crt;
var
n,i: integer;
result: real;
begin
clrscr;
write('Vvedite N: ');
readln(n);
if n>=1 then
begin
result:=sqrt(2);
for i:=1 to n-1 do
result:=sqrt(result+2);
writeln('Resultat: ',result:8:5);
end
else writeln('Oshibka! n<1!');
readkey;
end.