#include <bits/stdc++.h>
#include <cmath>

using namespace std;

#define REP(i,n)	for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REPS(i,s,n)	for(int i=(s), i##_len=(n); i<i##_len; ++i)

#define ALL(obj)	(obj).begin(),(obj).end()
#define sz(x) (int)(x).size()
#define v(T) vector<T>
#define VEC vector

typedef unsigned int 			uint;
typedef unsigned long long int	ull;
typedef long long int 			ll;

typedef pair<int,int>			P;
typedef vector<int>				Vint;
typedef vector<Vint>			VV;

template<typename T>string join(const v(T)&v)
{stringstream s;REP(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>inline ostream& operator<<(ostream&o,const v(T)&v)
{if(sz(v))o<<join(v);return o;}

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define MAX 		100010

const ll LINF = (ll)9e18+7;		//
const int INF = 100100100;			//2,147,483,647 (Max int)
const ll MOD = 1e9+7;
// テンプレ終了
//====================================================================//

// int DP[MAX];

//
int main(){
	ll a;cin >> a;

	ll t = 100;

	int cnt = 0;
	while(t < a){
		t += (ll)t/100;
		cnt ++ ;
		// cout << cnt << "\t" << t << endl;
	}

	cout << cnt << endl;	

	return 0;
}
 

