#include <stdio.h>

int main()
{
	long long int Year = 0;
	long long int Bank = 100;
	long long int X;

	scanf("%lld", &X);

	while (Bank < X) {
		Bank = (long long int)(Bank * 1.01);
		Year++;
	}

	printf("%lld\n", Year);

	return 0;
}