def szyfr(s):
t=""
for i in range(0, len(s)-1, 2):
t = t + s[i+1] + s[i]
if len(s)%2 != 0:
t=t + s[len(s)-1]
return t
print(szyfr("kotwica"))
ZGVmIHN6eWZyKHMpOgoJdD0iIgoJZm9yIGkgaW4gcmFuZ2UoMCwgbGVuKHMpLTEsIDIpOgoJCXQgPSB0ICsgc1tpKzFdICsgc1tpXQoJaWYgbGVuKHMpJTIgIT0gMDoKCQl0PXQgKyBzW2xlbihzKS0xXQoJcmV0dXJuIHQKcHJpbnQoc3p5ZnIoImtvdHdpY2EiKSk=