program p1;
var f,g:text;
uc,i,n,p,num:word;
nr:longint;
begin
assign(f,'fact.in');
reset(f);
assign(g,'fact.out');
rewrite(g);
read(f,p);
n:=0;    nr:=1;
while num<> p do
begin
num:=0;
for i:=1 to n do
nr:=nr*i;
while nr<>0 do
begin
uc:=nr mod 10;
if uc=0 then
num:=num+1;
nr:=n div 10;
end;
if num=p then
write(g,n)
else
inc(n);
end;
close(f);
close(g);
end.