#include<stdio.h>
int main(void)
{
	unsigned long long int x = 0,money = 100;

	int count = 0, yokin = 0;

	scanf("%lld", &x);

	while (1) {
		yokin = money / 100;
		
		money += yokin;

		count++;
		if (money >= x) {
			break;
		}
	}

	printf("%d\n", count);

	return 0;
}