var a, s , c, o: longint;
var fi, fo: text;
begin
assign(fi, 'input.txt'); reset(fi);
assign(fo, 'output.txt'); rewrite(fo);
readln(fi, s);
repeat
readln(fi, a);
if not a= 1 then
o:=o+1;
c:= c + 1;
until c = s;
write(fo, o);
close(fi);
close(fo);
end.