var f:text;i,k,p,c:longint;
begin
assign (f,'fact.in');
reset (f);
read (f,p);
close (f);
k:=0;
i:=0;
repeat
i:=i+5;
k:=k+1;
c:=i div 5;
repeat
if c mod 5=0 then k:=k+1;
c:=c div 5;
until (c=0) or (k=p);
until k=p;
assign (f,'fact.out');
rewrite (f);
write (f,i);
close (f);
end.