import math

def isprime(x):

#*******************Program*******************#

if x<=1:

return False

k=int(math.sqrt(x))

for j in list(range(2,k+1)):

if x%j==0:

return False

return True

#******************* End *******************#

def ismonisen(x):

if isprime(x) and isprime(2**x-1):

return True

else:

return False

if __name__ == "__main__":

try:

num_list = [2, 7, 11, 13, 21]

for num in num_list:

if ismonisen(num):

temp = 2 ** num - 1

print(temp, end = " ")

except ValueError:

print("输入数据错误！")