CSCHAN PASCAL

var n,d,x:longint;
begin
    assign(input,'CSCHAN.INP');reset(input);
    assign(output,',CSCHAN.OUT');rewrite(output);
    readln(n);    
    d:=0;
    while n>0 do
    begin
           x:=n mod 10;
           if x mod 2 = 0 then d:=d+1;        //inc(d);
           n:=n div 10;
    end;
    writeln(d);
end.