Nice program!!!
I didnt Care that
for around of niles
we should just calculate 2*r*pi!!!

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var
  r,x0,y0,x1,x2,y1,y2 :real;
  n,i                 :byte;
begin
  readln(n,r);
  r:=2*r*pi;
  readln(x0,y0); x1:=x0; y1:=y0;
  for i := 2 to n do
  begin
    x2:=x1; y2:=y1;
    readln(x1,y1);
    r:=r+sqrt(sqr(x1-x2)+ sqr(y1-y2));
  end;
    r:=r+sqrt(sqr(x0-x1)+ sqr(y0-y1));
  writeln(r:0:2);
  readln;
end.
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Aidin_n7