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

  for (let i = 1; true; i ++) {
    if (100 * 1.01 ** i <= a && 100 * 1.01 ** (i + 1) >= a) {
      ans = i;
      break
    }
  }

  console.log(ans);
  // console.log(Math.ceil((Math.log(a / 100) / Math.log(1.01))));
}

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