'use strict';
function Main(input) {
	input = input.split("\n")[0]
	let cnt = 0
    let a = 100
  	while(a !== input){
      a = Math.floor(a * 1.01)
      cnt = cnt + 1
      if(a == input){
        
		console.log(cnt)
      	return;
      }
    }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));