tak

def Reverse(x):
    xCount = x.__len__()
    y = 'a'

    for i in range(xCount):
        i = i + 1
        y = y + x[-i]

    y = y.strip('a')
    return y

def Prime(n):
    for i in range(2,int(n ** 0.5) + 1):
        if n % i == 0:
            return False

    return True

alsk = int(input("alsk: \n"))
alskB = True

for i in range(alsk):
    if Prime(i) is not True:
        continue

    elif Prime(i) is True:
        print Reverse(str(i))