const processData = (lines) => {
  const X = +lines[0]

  let a = 100
  let year = 0
  while(a<X) {
    year++
    a = Math.floor(a * 1.01)
  }
  console.log(year)
}

let i = ''
process.stdin.on('data', c => i += c)
process.stdin.on('end', () => {
  const {EOL} = require('os')
  const lines = i.split(EOL) /*your input text, split by lines*/
  processData(lines)
})
