program lx;
const
  filename='put';
  inf=filename+'.in';
  ouf=filename+'.out';
  maxn= ;
var
  i,j,k,l,m,n,sum:longint;
  a,f:array[1..10000]of longint;
  q:array[1..10000]of boolean;
function pan:boolean;
  var i:longint;
    begin
      pan:=true;
      for i:=1 to n do
        if f[i]=i then
          exit(false);
    end;
procedure dfs(k:longint);
  var i,j:longint;
    begin
      if k=n+1 then
      begin
        if pan then inc(sum)  end
          else
            begin
              for i:=1 to n do
                if q[i] then
                  begin
                    q[i]:=false;
                    f[k]:=i;
                    dfs(k+1);
                    q[i]:=true;
                  end;
            end;
    end;

begin
  assign(input,inf); reset(input);
  assign(output,ouf);rewrite(output);
  readln(n);


  fillchar(q,sizeof(q),true);
  sum:=0;
    dfs(1);
    writeln(sum);
  close(input);close(output);
end.