#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef long long ll;

int main()
{
	ll X;
	scanf("%lld", &X);
	ll a = 100;
	ll i = 0;
	while (a < X)
	{
		a = ((ll)a*1.01);
		i++;
	}
	printf("%lld",i);
	return (0);
}

