USES CRT;VAR N,I,SO,CODE,X
Bài 1:
uses crt;
var n,i,so,code,x:integer;
f,g:text;
c,s:string;
h:int64;
begin
clrscr;
assign(f,'persist.inp');
reset(f);
assign(g,'persist.out');
rewrite(g);
readln(f,n);
str(n,s);
while length(s)<>1 do
begin
x:=x+1; h:=1;
for i:=1 to length(s) do
begin
val(s[i],so,code);
h:=h*so;
end;
str(h,s);
end;
writeln(x);
close(f);
close(g);
readln;
end.