#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <math.h>
#include <tuple>

#include <set>
#include <unordered_map>
#include <stack>
#include <map>

using namespace std;

#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)
#define all(x) (x).begin(),(x).end()
using ll = long long;
template<class T>bool chmaxj(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; }
void YesNo(bool y) { cout << (y ? "Yes" : "No") << endl; } //true==yes


#define INF 21474836

//////////////////////////////////////////////////////////////



int main() {

	long long X;
	cin >> X;

	long long e = 100;
	long long Y = 0;
	while (e < X) {
		e = e * 1.01;
		Y++;
	}
	
	cout << Y << endl;

}
