text: let rl = require("readline").createInterface(process.stdin, process.stdout);
  
  rl.on("line", (line) => {
    console.log(compute(parseInt(line)));
  });
  
  let compute = function (n) {
    if (n < 0) return 0;
    if (n === 0) return 1;
    return compute(n - 1) + compute(n - 3);
  };
  