Java-Code

class Primzahlen {
	
	
	public static void main(String[] args) {
	
		int zaehler = 0;
		
		for(int i = 12; i<1000000; i++) {
			boolean prim1 = true;
			
			for(int j = 2; j <= Math.sqrt(i); j++ ) {
				if(i%j == 0) {
					prim1 = false;
					break;
				}
			}
			if(prim1) {
				boolean prim2 = true;
				
				for(int j = 2; j <= Math.sqrt(drehen(i)); j++ ) {
					if(drehen(i)%j == 0) {
						prim2 = false;
						break;
					}
				}
				if(prim2 && i != drehen(i)) {
					zaehler++;
				}
			}
		}
		System.out.print(zaehler);
		
	}
	
	public static int drehen(int i) {
		int zahl = i;
		int umdrehen = 0;
		
		while(zahl>0) {
			umdrehen = umdrehen*10 + zahl%10;
			zahl /= 10;
		}
		return umdrehen;
 	}
}