function Main(input){
    input = input.split(" ");

    var a = parseInt(input[0], 10);
    var b = parseInt(input[1], 10);

    if(b%a == 0){
      console.log(a+b);
    }else{
      console.log(b-a);
  }
}
   
  Main(require("fs").readFileSync("/dev/stdin", "utf8"));