#include<stdio.h>
#include<math.h>
int main() {
	long long int a = 0;
	long long int b = 100;
	int c = 0;
	scanf("%lld", &a);
	for (int i = 1; i <= 3760; i++) {
		b = b * 1.01 / 1;
		if (b >= a) {
			c = i;
			break;


		}
	}
		printf("%d", c);
		return 0;
}