#include<stdio.h>
int main() {
    int number;
    int sum = 0;
    int count = 0;
    float average;
    printf("Please enter the numbers (0: quit): \n");
    do {
        scanf("%d", &number);
        if(number != 0) {
            sum = sum + number;
            count = count + 1;
        }
    } while(number != 0);
    average = (float) sum / count;
    if(count == 0) {
        printf("The average is N/A.\n");
    }else {
        printf("The average is %f.\n", average);
    }
    return 0;
}