#include <stdio.h>
int main(void) {

	long long int money = 100;

	double   interest = 0.01;

	long long int targetValue = 0;

	scanf("%d%*c", &targetValue);

	int year = 0;

	while (targetValue > money)
	{
		money = money+money/100;

		year++;

	}

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

	return 0;
}