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

long long n;
long long now = 100;

int main(){
	scanf("%lld", &n);
	long long k = 1;
	while(1){
		now = (long long)((double)now) * 1.01;
		if(now >= n){
		    cout << k;
		    break;
		}
		k++;
	}
	return 0;
}