#include <stdio.h>

int	main()
{
	long long X, sum;

	scanf("%lld\n", &X);
			// printf("%lld\n", X);
	sum = 0;
	for (long long i = 100; i < X; i *= 1.01)
	{
		// printf("%d\n", i);
		sum++;
	}
	printf("%lld\n", sum);
	return 0;
}