function main(final) {
  	let amount = 100;
  	let year = 0;
  	
  	while(amount <= final) {
      amount = Math.floor(amount + (amount * 0.01));
      year++;
    }
  
  	console.log(year);
}
const input = require('fs').readFileSync('/dev/stdin', 'utf8');

main(parseInt(input));
