'use strict';
function main(input) {
  const
    arr = input.trim().split('\n');
  let
    a = Number(arr[0]),
    money = 100,
    i = 0;

  while (money < a) {
    money * 1.01;
    i ++;
  }

  console.log(i);
}

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