#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int main(void){
	long long X,N;
	int i;
	char str[10000000],buf[10000000];
 
	fgets(str, sizeof(str), stdin);
	X=strtoll(strtok(str," "),buf,10);

	N=100;i=0;
	while(1){
		if(N>=X) break;
		i++;
		N=N*1.01;
	}

	printf("%ld\n",i);

	return 0;
}