function main(input) {
  input = input.split('\n');
  const first = BigInt(input[0]);

  let year = 1;
  let stock = BigInt(100);
  while (stock < first) {
    stock = BigInt(Math.floor(Number(stock) * 1.01))
    if (stock >= first) {
      console.log(year)
      break
    }

    year++;
  }
}

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