program Program3;
var m,n: integer; mark: Boolean;
function test(m,N:integer):integer;
var i,p: integer; flag: boolean;
begin
m := m - 1; i := 0; flag := False;
for p:= 2*N downto (N+1) do
begin
i:= (i+m) mod p;
if (i
begin
test := 0; flag := Ture; Break;
end
end;
if not(flag) then test:=1;
end;
begin
read(n); m:=1; Mark := False;
repeat
if (test(m,n)=1) then
begin writeln(m); break; end;
m:= m+1;
until Mrak;
end.
输入：7 输出_________
