calcul sin(1)

{calcul sin(1)}
uses wincrt;
var n:integer;
(**********************************)
function somme(n:integer):real;
var s:real;
i,signe:integer;
{============================}
function fact(n:integer):longint;
var i:integer;
f:longint;
begin
f:=1;
for i:=2 to n do f:=f*i;
fact:=f;
end;
{============================}
begin
s:=1; i:=1; signe:=1;
repeat
i:=i+2;
signe:=-signe;
s:=s+signe/fact(i);
until i>=n;
somme:=s;
end;
(**************** P.P *******************)
begin
repeat
write ('N = '); readln(n);
until n in [5..30];
writeln (somme(n):2:8);
end.