#include<stdio.h>
int main(){
    int n;
    printf("Enter the number of book IDs:");
    scanf("%d",&n);
    if (n < 0){
        printf("Invalid input\n");
        return 1;
    }
    int bookIDs;
    printf("Enter %d book IDs:",n);
    for(int i =0; i < n; i++){
        if (scanf("%d",&bookIDs [i]) !=1){
            printf("Invalid input");
            return 1;
        }
    }
    return 0;
}