# PMAT-502ar (Tranche 2): positional list insertion xs.insert(i, x).
def ins_mid(xs: list[int], x: int) -> int:
xs.insert(1, x)
return xs[1]
def ins_front(xs: list[int]) -> int:
xs.insert(0, 99)
return xs[0]
def ins_grows(xs: list[int]) -> int:
xs.insert(1, 7)
return len(xs)