var f,g:text;
    ct,i,p,a:int64;

BEGIN
assign(f,'fact.in');
reset(f);
read(f,a);
close(f);

ct:=0;
p:=1;
i:=0;

repeat
i:=i+5;
p:=((p mod 10)* i mod 10) mod 10;
if (p = 0) or (i mod 10 = 0 ) or (p =5 ) or (p mod 10 = 5) then

 begin
 ct:=ct+1;
 p:=1 mod 10;
 end;

until ct = a;
assign(g,'fact.out');
rewrite(g);
writeln(g,i);
close(g);
END.