#include<iostream>
#include<string>
using namespace std;
{
string checkEligibility(int age)
if (age < 0)
{
    return "Invalid input";
}
else if (age >= 18)
{
    return "Eligible";
}
else
{
    return " Not eligible";
}
}
int main()
{
    int age;
    cout << "Enter age: ";
    cin >> age;
    cout << checkEligibility(age) << endl;
    return 0;
}