const Main = input => {
    const x = parseInt(input, 10);
    let yokin = 100;
    let count = 1;
    while(true) {
        yokin += Math.floor(yokin * 0.01);

        if(yokin >= x) break;
        count++;
    }
    console.log(count);
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));