var
x, counter : integer;
begin
readln(x);
x := abs(x);
while x > 0 do
if (x mod 10 = 0) then
counter := counter + 1;
x := x div 10;
end;
writeln(counter);
end.
var
x, counter : integer;
begin
readln(x);
x := abs(x);
while x > 0 do
begin
if (x mod 10 = 0) then
counter := counter + 1;
x := x div 10;
end;
writeln(counter);
end.