'use strict';
const main = arg => {
  const input = arg.trim().split(' ');
  const target = parseInt(input[0], 10);

  let value = 100;
  let n = 0;
  while(value < target) {
    value = Math.floor(value * 1.01);
    n++
  }
  console.log(n);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));