function Main(input){
    input=input.split("\n");  //ここまで必須
    var sum=100;
    var year=0;
    while (sum<input[0]){
        sum=Math.floor(sum*1.01);
        year=year+1;
    }
    console.log(year);
}

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