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

#define rep(i,k,n) for(int (i)=(k);(i)<(n);(i)++)
#define max(a,b) (a)>(b)?(a):(b)
#define min(a,b) (a)<(b)?(a):(b)
#define abs(a,b) (a)< 0 ?(a):-(a)
#define llong long long

int main(){
	llong X; scanf("%lld",&X);
	llong money=100;
	int year=0;
	while( money<X ){
		money = money + money/100;
		year++;
	}
	printf("%d",year);
	return 0;
}
