begin
var (s, i, z) := (0.0, 0, 1);
var a: real;
repeat
Inc(i);
a := 2 * i - 1;
s += z / a;
z := -z;
until 1 / a < 1e-4;
s.Println
end.
begin
var (s, i, z) := (0.0, 0, 1);
var a: real;
repeat
Inc(i);
a := 2 * i - 1;
s += z / a;
z := -z;
until 1 / a < 1e-4;
s.Println
end.
0.785448153398948