#include<stdio.h>
#include<math.h>
int main(void) {
	int i, X, kane = 100;
	
	scanf("%d", &X);
	
	if (101 <= X <= pow(10,17)) {
		for (i = 0; X>kane; i++) {
			kane = kane * 1.01;
		}
	
		
	}else if (X == pow(10, 18)) {
		i = 3760;
	}printf("%d", i);
	return 0;
}