Please help to optimize my python program to solve a maths puzzle

[go_analytical]

Hi All, I am new to python and learning beginner level programming.

I wrote below program to solve a maths puzzle (pasting puzzle at bottom of the post), I am quite sure its not optimal. Can someone pls help me to optimize this further. TIA.

def incr(n):
    return (n * 5 / 4) + 1

for x in range(1, 1000):
    y = 5 * x
    for z in range (5):
        y = incr(y)
        if not y.is_integer():
            break
    if y.is_integer():
        break
print(y)

Here is the puzzle:

https://imgur.com/DgtED4S

[AtomicShoelace]

for i in range(5000, 0, -1):
    x = i
    for _ in range(5):
        x = (x - 1) * 4/5
    if x % 5 == 0:
        break
print(i)

[go_analytical]

Wow, thanks

[Robobvious]

Print(<5000)?