function Main(input: string): void {
  const inputNumbers = input.split("/n");
  const X = Number(inputNumbers[0]);
  const Y = Number(inputNumbers[1]);
  const L = Number(inputNumbers[2]);
  let numCommand = 0;
  if(X >= 0){
    numCommand += X%L;
    if(Y != 0){
      numCommand++;
      numCommand += Y%L;
    }
  } else {
    numCommand++;
    numCommand += Y%L;
    numCommand++;
    numCommand += X%L;
  }
  console.log(numCommand);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));