public class MyClass {
private static boolean is_prime(int n) {
if (n == 2) {
return true;
}
if (n < 2 || n % 2 == 0) {
return false;
}
for (int i = 3; i * i <= n; i += 2) {
if (n % i == 0) {
return false;
}
}
return true;
}
private static int cyclically_rotate_left(int n) {
int m = n;
int p = 1;
while (m >= 10) {
p *= 10;
m /= 10;
}
return (int)(m + 10 * (n % p));
}
private static boolean is_circular_prime(int n) {
if (!is_prime(n)) {
return false;
}
int rotated_n = cyclically_rotate_left(n);
while (rotated_n != n) {
if (rotated_n < n || !is_prime(rotated_n)) {
return false;
}
rotated_n = cyclically_rotate_left(rotated_n);
}
return true;
}
public static void main(String args[]) {
// 3779 = prime
// 7793 = prime
// 7937 = prime
// 9377 = prime
int n = 2;
for (int i = 0; i < 18; n++) {
if (is_circular_prime(n)) {
if (i > 0) {
System.out.print(", ");
}
System.out.print(n);
i++;
}
}
}
}
/*
run:
2, 3, 5, 7, 11, 13, 17, 37, 79, 113, 197, 199, 337, 1193, 3779, 11939, 19937, 193939
*/
