#include<cmath> #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> using namespace std; int cnt = 0; int s1(int x){ if(x <= 1) return 0; for(int i = 2;i * i <= x;i++) if(!(x % i)) return 0; return 1; } int main(){ int m,n; cin >> m >> n; for(int i = m;i <= n;i++){ int ge = i % 10; int shi = i / 10; if(s1(i) && s1(10 * ge + shi)){ cnt++; if(cnt == 1) cout << i; else cout << "," << i; } } return 0; }