#include <stdio.h>

int main()
{
	int k;
	long long X, tmp = 100;
	scanf("%lld", &X);
	for (k = 0; tmp < X; k++, tmp = (long long)((long double)tmp * 101 / 100));
	printf("%d\n", k);
	fflush(stdout);
	return 0;
}