Spring =2, summer = 1, autumn =7, winter =8.

If spring, summer, autumn and winter +4= winter, autumn, summer and spring, it is not established.

No positive integer can satisfy the above equation.

Prove as follows

Use a, b, c and d to represent spring, summer, autumn and winter respectively.

a * 1000+b * 100+c * 10+d+4 = d * 1000+c * 100+b * 10+a

That is 999a+90b+4=999d+90c.

999(a-d)+4=90(c-b)

A, b, c and d are all positive integers.

If a>b, a-b≥ 1

The left side of the equation is ≥ 1003.

If a<b, a-b≤- 1

The left side of the equation is ≤-995.

8≤(c-d)≤-8。

Then 720≤ the right side of the equation ≤-720

Therefore, there is no intersection between the value ranges on the left and right sides of the equation.

That is to say, no matter what the four numbers take, the equation cannot be established.