#include <stdio.h>
#include <ctype.h>
#include <string.h>


int main() {
	long int X;
	int i=0;
	int m = 100;
	scanf("%ld", &X);
	while (1) {
		if (m >= X) {
			break;
		}
		m = m * 1.01;
		
		i = i + 1;
	}
	printf("%d", i);
	return 0;
}
