Your firm currently has $100 million in debt outstanding with a 10% interest rate. The terms of the loan require the firm to repay $25 million of the balance each year. Suppose that the marginal corporate tax rate is 25%, and that the interest tax shields have the same risk as the loan. Assume that the loan balance at the end of the prior year determines the interest paid in a given year. What is the present value of the interest tax shields from this debt?