#include <stdio.h>

int main(){
	
	long int x,money=100;
	long int cnt=0;
	
	scanf("%ld",&x);
	
	do{
		money = money + (money*0.01); 
		cnt = cnt + 1;
		
//		printf("money = %ld  cnt = %ld  ",money,cnt);
	
	} while(money < x);
	
	printf("%ld",cnt);
	
	return 0;
}
