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



int main()
{
	long long int X=0,money=100;
	
	
	scanf("%lld",&X);

	int year=0;
	
	while(money<X){
		
		money=1.01*money;
		year++;
	}
	
	printf("%d", year);
	

	return 0;
}
