function main(arg) {
  const inputs = arg.split("\n");
  const x = inputs[0];
  
  const rate = 1.01;
  
  let counter = 0;
  let credit = 100;
  
  while( credit < x ) {
    credit = Math.floor(credit * rate);
    counter++;
  }
  
  console.log(counter);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));