#include <stdio.h>

int main(void) {
	long long x;
	scanf("%lld", &x);
	long long a = 100;
	int year = 0;
	while (a < x) {
		 a = long long(a * 1.01);
		year = year + 1;
	}
	printf("%d", year);

	return 0;
}