function main(input) {
  var x = parseInt(input, 10);
  var saving = 100;

  var isLower = true;
  var forYear = 0;
  while (isLower) {
    forYear += 1;
    saving = Math.floor(saving * 1.01);
    if (saving >= x) isLower = false;
  }
  console.log(forYear);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));
