var a,b:array[1..11] of int64;
    n,m,k:int64; f:text;

procedure putere;
var i:byte; k:int64;
begin
 k:=1;
 for i:=1 to 11 do begin k:=k*5; a[i]:=k; end;
end;

procedure aras;
var i:byte;
begin
 k:=1; m:=5;
 while k<n do
  begin
   inc(i);
   m:=m+5;
   k:=0;
   for i:=1 to 11 do
    begin
     b[i]:=m div a[i];
     k:=k+b[i];
    end
  end;
end;

begin
 assign(f,'fact.in');
 reset(f);
 readln(f,n);
 close(f);
 putere;
 aras;
 assign(f,'fact.out');
 rewrite(f);
 if k=n then writeln(f,m) else writeln(f,'-1');
 close(f);
end.