Given an integer, num, convert it to its Roman numeral representation.

Roman numerals are built using the following $7$ symbols:

Roman numerals are constructed by converting each decimal place value from highest to lowest using these rules:

• If the value does not start with $4$ or $9$, select the largest symbol whose value can be subtracted from the current value, append it to the result, subtract its value, and repeat for the remainder.

• If the value starts with $4$ or $9$, use its subtractive form: one smaller symbol placed before a larger one. Only the following subtractive forms are valid: $4$ (IV), $9$ (IX), $40$ (XL), $90$ (XC), $400$ (CD), and $900$ (CM).

• Only powers of $10$ ( I, X, C, M ) may be repeated consecutively, and at most $3$ times. The symbols V, L, and D may never be repeated. If a symbol would need to appear $4$ times, use the corresponding subtractive form instead.

Note: Conversion is applied digit by digit based on decimal place values. For example, $49$ is not treated as $1$ less than $50$; instead, $40$ becomes XL and $9$ becomes IX.

Constraints:

• $1 \leq$ ...