#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<(int)(n);i++)

int main(){
    long long int X;
    cin >> X;

    int count = 0;
    long long int total = 100;
    
    for(int i=0;;i++) {
        count += 1;
        total = (total*101)/100;
        if(total>=X){
            break;
        }
    }

    cout << count << endl;
}