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

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

  console.log(res);
}

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