Here is a quick one
def main():
words = str(input("Input Sentence:")).split()
for word in words:
print(word[1:] + word[0] + "ay", end = " ")
print ()
main()
A better solution would probably use list comprehension so you could actually use the output, but this does what you asked.
EDIT:
This works for python3.x
If you want it to work for python2 you are going to have a bit more fun. Just add the strings together for each word, then print the result string.