def isPrime(n): if n<2: return False for x in range(2,int(n**0.5+1)): if n%x ==0: return False return True res =[] m,n = list(map(int,input().split())) for x in range(m,n+1): y = int(str(x)[::-1]) if isPrime(x)+isPrime(y)==2: res.append(str(x)) if len(res)>0: print(','.join(res)) else: print("No")