"use strict"
function main(arg) {
    let X = Number(arg.trim().split("\n")[0])
    let sum = 100
    let i = 1
    for (i = 1; ; i++) {
        sum = Math.floor(sum + sum * 0.01)
        if (sum >= X) {
            break
        }
    }
    console.log(i)
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));