sum = 0                          sum = 0
x = 1                            x = 1
n = 1                            n = 1
while True:                      while Ture:
    if n > 20:                       sum = sum + x
        break                        x = x * 2
    sum = sum + x                    n = n + 1
    x = x * 2                        if n > 20:
    n = n + 1                            break
print sum                         print sum