#include<stdio.h>
#include<math.h>
int main(void) {
	int i, X, kane = 100;
	
	scanf("%d", &X);
	
	
		for (i = 0; X>kane; i++) {
			kane = kane + kane/100;
		}
	
		
	
		
	printf("%d\n", i);

	return 0;
}