#include<stdio.h>

int main(void) {
	unsigned long x=0, bank=0;
	
	
	scanf("%ld", &x);
	
	bank = 100;
	for (int i = 1;;i++)
	{
		bank *= 1.01;

		if (bank>=x)
		{
			printf("%d\n",i);
			break;
		}
		
	}
	
	
	return 0;
}