#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define INF 2e9
#define ALL(v) v.begin(), v.end()
using namespace std;
typedef long long ll;

void Main()
{
  ll x;
  cin >> x;
  
  
  int count = 0;
  ll mint = 100;
  
  while(mint < x){
    mint = mint *1.01;
    
    count++;
  }
  
  printf("%d", count);
}

int main()
{
  std::cout << std::fixed << std::setprecision(15);
  Main();
}