"use strict";
    
const main = arg => {
    arg = arg.trim().split("\n");
    const X = BigInt(arg[0].split(" ")[0]);
    let now = 100;
 	let cnt = 0;
  
    while(BigInt(now) < X) {
      now += Math.floor(now * 0.01);
      cnt++;
    }
    
    console.log(cnt);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));