$($$ in millions$)$ Debit$($Credit$)$ PBO Plan Assets Prior Service Cost Net $($Gain$)/$Loss Pension Expense Cash Net Pension $($Liability$)/$Asset

Beginning balance $451615651$

Service cost $(86)$

Interest cost $(26)$

Expected return on assets $56$

Gain$/$loss on assets $4$

Amortization of:

Prior service cost

Net gain$/$loss $(2)$

Loss on PBO $(66)$

Contributions to fund $41$

Retiree benefits paid

Ending balance $(531)54123$

What was Ng$\text{'}$s pension expense for the year?