Implement a function that merges two already sorted integer runs into out, ascending, taking the value from left whenever the two fronts are equal.

• left holds ln integers and right holds rn, both sorted in ascending order already. Grademe never hands you an unsorted run, so you have nothing to check there.
• out points to a buffer with room for exactly ln + rn integers. Fill it with every value of both runs, ascending. The examples print out as its values separated by single spaces.
• Write ln + rn values and stop. Whatever sits at out[ln + rn] belongs to the caller.
• When the front of left and the front of right hold the same value, take the one from left. Two equal integers look the same once written, so the rule costs you nothing here, and it is what makes a merge sort built on this function stable.
• Both runs are const. Read them, never write through them, and do not reorder them.
• ln of 0 means the answer is right copied over, rn of 0 means it is left. Once one side is exhausted, the rest of the other side lands in out in order.
• With ln and rn both 0 there is nothing to write. Leave out exactly as you found it.
• The two runs can be wildly different sizes. A single value on one side against eight on the other has to come out in the right slot.

Implement a function that merges two already sorted integer runs into out, ascending, taking the value from left whenever the two fronts are equal.

• left holds ln integers and right holds rn, both sorted in ascending order already. Grademe never hands you an unsorted run, so you have nothing to check there.
• out points to a buffer with room for exactly ln + rn integers. Fill it with every value of both runs, ascending. The examples print out as its values separated by single spaces.
• Write ln + rn values and stop. Whatever sits at out[ln + rn] belongs to the caller.
• When the front of left and the front of right hold the same value, take the one from left. Two equal integers look the same once written, so the rule costs you nothing here, and it is what makes a merge sort built on this function stable.
• Both runs are const. Read them, never write through them, and do not reorder them.
• ln of 0 means the answer is right copied over, rn of 0 means it is left. Once one side is exhausted, the rest of the other side lands in out in order.
• With ln and rn both 0 there is nothing to write. Leave out exactly as you found it.
• The two runs can be wildly different sizes. A single value on one side against eight on the other has to come out in the right slot.