/* Test n, reverse(n) for primeness. */

#include <stdio.h>
int isPrime(int n);
int reverse(int n);

int
main()
{
    int	limit, n, r;
    printf("Enter limit: ");
    scanf("%d", &limit);
    for (n = 2; n <= limit; ++n) {
	if (isPrime(n)
	     && isPrime(r = reverse(n))) {
	    printf("%d and %d are prime.\n",
		   n, r);
	}
    }
    return 0;
}