#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

int main(){

    ll x;
    cin>>x;

    int cnt = 0;
    ll sum = 100;

    while(sum < x){
        ll add = sum/100;
        sum += add;
        cnt++;
    }

    cout<<cnt<<endl;

    return 0;
}