#include <stdio.h>

int main() 
{
    int a;
    scanf("%d",&a);
    switch (a)
        {
            case 18:
                {
                    printf("not eligible for voting");
                    break;
                }
            case 20:
                {
                    printf("eligible for voting");
                    break;
                }
            default:
                {
                    printf("the input should be only 18 or 20");
                }
        }
    return 0;
}