Design A DS That Support Insert, delete, Get Operation in O(1) e.g Consant Time

Design a Data Structure with following operations
1.Insert(X) -> insert X if X not present
2.Delete(X) -> delete X if X present
3.Get() -> return any element if it is present

all operations in O(1).
No memory constraint.

Init:

k=0

Insert X:

k = k+1 mod m;
A[X] = k;
B[k] = X;

Search X:

return (A[X] < m) and (B[A[X]] == X)

Delete X:

A[X] = 0;
B[k] = 0;
k = k-1;