var f:text;
    p,n,i,j:longint;

function nrz(n:longint):longint;
var q:longint;
begin
   q:=0;
   while n>0 do begin
      q:=q+n div 5;
      n:=n div 5;
   end;
   nrz:=q;
end;

begin
 assign(f,'fact.in');
 reset(f);
 readln(f,p);
 close(f);

 i:=0;
 if p=0 then n:=1
 else n:=0;
 while i<p do begin
   inc(n,5);
   i:=nrz(n);
 end;


 assign(f,'fact.out');
 rewrite(f);
 writeln(f,n);
 close(f);
end.