uses crt;
var n,i:integer;
p:real;
begin
clrscr;
write('n=');
readln(n);
p:=1;
for i:=1 to n do
p:=p*(2*i)/(2*i+1);
write('P=',p:0:4);
readln
end.
uses crt;
var n,i:integer;
p:real;
begin
clrscr;
write('n=');
readln(n);
p:=1;
for i:=1 to n do
p:=p*(2*i)/(2*i+1);
write('P=',p:0:4);
readln
end.