program pascal;
var f,g:text;
    ok:boolean;
    j:longint;
    nr5,p,i,aux,z,t:int64;
begin
 assign(f,'fact.in'); reset(f);
 assign(g,'fact.out'); rewrite(g);
 read(f,p);
 i:=0;
 ok:=false;
 nr5:=0;
 repeat
   begin
      i:=i+5;
      aux:=i;
      while (aux mod 5=0) do
        begin
        aux:=aux div 5;
        inc(nr5);
        end;
     if nr5>p then ok:=true;
   end;
 until (nr5=p) or (ok);
 if ok then write(g,-1)
      else write(g,i);
close(f);
close(g);
end.