#include<stdio.h>
#include<math.h>

int main()
{
        double Y;
	double X = 100.0;
	long long n=0;


	scanf("%lf",&Y);
	while(X<Y)
	{
		X=floor(X*1.01);
		n++;
	}
	printf("%lld\n",n);
	return 0;
}
