Suppose Caterpillar, Inc., has 672 million shares outstanding with a share price of $72.85, and $24.43 billion in debt. If in three years, Caterpillar has 695 million shares outstanding trading for $82.85 per share, how much debt will Caterpillar have if it maintains a constant debt-equity ratio? The amount of debt required in three years will bes billion. (Round to two decimal places.)