int A = 99;
            int B = 10001;
            int count1 = 0;
            int sum = 0;
            int a = A;
            while(a != 0) {
                sum += a % 10;
                a /= 10;
            }
            a = A;
            bool parity = false;
            if(sum % 2 == 0) {
                count1++;
                parity = true;
            }
            while(a < B) {
                a++;
                if(a % 10 != 0)
                    parity = !parity;
                if(parity)
                    count1++;
            }
            int count2 = 0;
            for(int i = A; i <= B; i++) {
                sum = 0;
                int temp = i;
                while(temp != 0) {
                    sum += temp % 10;
                    temp /= 10;
                }
                if(sum % 2 == 0)
                    count2++;
            }
            Console.WriteLine(count1);
            Console.WriteLine(count2);
            Console.ReadLine();