nclude <stdio.h>

int main() {
    double sum = 0, num = 0;
    long int number = 0;
    do {
        scanf("%ld", &number);
        if (number <= 0) {
            if (num == 0 && number != 0) {
                printf("no_entries ");
            } else {
                switch (number) {
                    case 0:
                        printf("\b");
                        return 0;
                    case -1:
                        printf("%.2f ", (double) (sum / num));
                        break;
                    case -2:
                        printf("%.2f ", (double) sum);
                        break;
                }
            }
        } else {
            sum += number;
            num++;
        }
    } while (number != 0);
    return 0;
}