function Main(input: string) {
  const inputs = input.split("\n");
  const X = Math.abs(Number(inputs[0]))
  const Y = Number(inputs[1])
  const L = Number(inputs[2])
  
  let count = 0
  
  if (Y != 0) {
  	count += Math.ceil(Y/L)
  	if (Y < 0) {
  		count += 1
  	}
  }
  if (X != 0) {
  	count += 1
	count += Math.ceil(X/L)
  }
  
  console.log(count)
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));