function Main(input) {
  "use strict";
	const lines = input.split("\n");
  const line1 = lines[0].split(" ");
  let nums = line1.map(s => parseInt(s, 10));
  let t = nums.pop();
  let b = nums.pop();
  let a = nums.pop();
  console.log( Math.floor((t+0.5)/a)*b)
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));