#include<bits/stdc++.h>
using namespace std;
#define int long long
#define M 1000000007
//#define M 998244353
const int inf=4e18;
int32_t main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);cout.tie(NULL);
	int x;cin>>x;
	int c=100,o=0;
	while(c<x)
	{
		c=(101*c)/100;
		o++;
	}
	cout<<o<<endl;
}