
#include<stdio.h>

int main()
{
	long long now=100;
	long long x=0;
	int count=0;
	scanf("%lld",&x);
	while(1)
	{
		if(now>=x)break;
		else
		{
			now*=1.01;
			count++;
		}
	}
	printf("%d",count);
}