process.stdin.resume();
process.stdin.setEncoding('utf8');

var lines = []
var reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

reader.on('line', (line) => {
  lines.push(line);
});

reader.on('close', () => {
 var x = Number(lines[0]);
 var a = 100;
 var year = 0;
 while(true){
   if(a >= x){
     break;
   }
   a = Math.floor(a * 1.01);
   year++;
 }

 console.log(year);
});