#include <bits/stdc++.h>
using namespace std;
int s(int n){
	int i,c=0;
	for(i=2;i<=sqrt(n);i++){
		if(n%i==0){
			c=1;
			break;
		}
	}
	return c;
}
int main(){
	int i,n,j,h=0,g;
	for(i=10;i<=1000;i++){
		j=i;
		h=0;
		while(j!=0){
			g=j%10;
			j=j/10;
			h=h*10+g;
		}
		if(s(h)==0&&h==i){
			cout<<i<<endl;
		}
	}

    return 0;
}
/**************************************************************
	Problem: 1142
	User: 15159808820
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/