'use strict';
function main(input) {
    var args = input.trim().split('\n')[0]
  	let a = 100
    let cnt =0
    while(true){
    a = a * 1.01
      cnt = cnt + 1
      if(a === args){
    console.log(cnt)    
    }
  	
  	
}
 
main(require('fs').readFileSync('/dev/stdin', 'utf8'));