type
vector=array[1..13] of longint;
const v:vector= (5,25,125,625,3125,15625,78125,390625,1953125,9765625,48828125,244140625,1220703125);
const p:vector= (1,6,31,156,781,3906,19531,97656,488281,244146,12207031,61035156,305175781);
var i,n,k:longint;
    f:text;
  begin
  assign(f,'fact.in');
  reset(f);
  read(f,n);
  if n=0 then k:=1
         else while n>5 do
              begin
              i:=1;
                while n>v[i] do
                inc(i);
               k:=k+p[i];
               dec(n,v[i]);
               end;
       close(f);
       assign(f,'fact.out');
       rewrite(f);
       write(f,k);
       end.