include <stdio.h>
int main() {
    int age;
    printf("Enter the age: ");
    scanf("%d", &age);
    if (age < 0) {
        printf("Invalid input\n");
    } else if (age >= 18) {
        printf("Eligible\n");
    } else {
        printf("Not eligible\n")
    }
    return 0;
}