#include<stdio.h>

int main() {
	int y = 100, x;
	int f = 0, i = 1;
	scanf("%d", &x);
	while (f == 0) {
		y = y*101;
		y = y / 100;
		if (y >= x) {
			f++;
		}
		else {
			i++;
		}
	}
	printf("%d", i);
}