#include <stdio.h>
typedef long long ll;
int main() {
	ll x, m = 100;
	int y = 0;
	scanf("%lld", &x);
	while (1) {
		m = m * 1.01;
		y++;
		if (m >= x) {
			break;
		}
	}
	printf("%d\n", y);
	return 0;
}