function main(input) {
  const lines = input.trim().split("\n");
  const X = lines[0];

  let d = 100;
  let res = 0;
  while (d < X) {
    d += Math.floor(d / 100);
    res++;
  }

  console.log(res);
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));