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

#define ms(s, n) memset(s, n, sizeof(s))
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORd(i, a, b) for (int i = (a) ; i >= (b); i--)
#define FORall(it, a) for (__typeof((a).begin()) it = (a).begin(); it != (a).end(); it++)
#define sz(a) int((a).size())
#define present(t, x) (t.find(x) != t.end())
#define all(a) (a).begin(), (a).end()
#define uni(a) (a).erase(unique(all(a)), (a).end())
#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define sp system("pause")
#define prec(n) fixed<<setprecision(n)
#define bit(n, i) (((n) >> (i)) & 1)
#define bitcount(n) __builtin_popcountll(n)
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pi;
typedef vector<int> vi;
typedef vector<pi> vii;
const int MOD = (int) 1e9 + 7;
const int INF = (int) 1e9;
const ll LINF = (ll) 1e18;
const ld PI = acos((ld) -1);
const ld EPS = 1e-9;
const int N = (int) 1e5 + 10;
void TimeExecution() {
    cout << "\n\n===>> Time Execution: " << clock() / (double)1000 << " sec(s).";
}
ll sqr(ll a)
{
    return ((a % MOD) * (a % MOD)) % MOD;
}
ll msub(ll a, ll b)
{
    return ((a - b) % MOD + MOD) % MOD;
}
ll madd(ll a, ll b)
{
    return (a + b) % MOD;
}
ll mmul(ll a, ll b)
{
    return ((a % MOD) * (b % MOD)) % MOD;
}
int t;
int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    /*
    #ifndef ONLINE_JUDGE
        freopen("in.txt", "r", stdin);
        freopen("out.txt", "w", stdout);
    #endif
    */
    ll x;
    cin >> x;
    ll a = 100;
    ll d = 0;
    while(a < x)
    {
        a += (a / 100);
        d++;
    }
    cout << d;
    return 0;
}
