import sys
def add_number(x):
# double every other
d = []
for o, n in enumerate(x):
if (o % 2):
d.append(int(n)*2)
else:
d.append(int(n))
# sum the numbers
total = 0
for n in d:
for c in str(n):
total += int(c)
return total
def add_check(x):
print "{} check: {}".format(x, add_number(x) * 9 % 10)
def verify_check(x):
total = add_number(x[:-1])
if (total * 9 % 10) == int(x[-1]):
return True
return False
if __name__ == '__main__':
if len(sys.argv) != 2:
add_check(sys.argv[2])
else:
print verify_check(sys.argv[1])