#include<stdio.h>
#include<string.h>
#include<math.h>
#include <stdlib.h>
#include<ctype.h>
#include<limits.h>

//qsort
int compare_int(const void *a, const void *b)
{
    return *(int*)a - *(int*)b;
}

//比較
int max(int a, int b){
	if (a>b) return a;
	else return b;
}

int min(int a,int b) {
	if(a>b) return b;
	else return a;
}


//main関数
int main() {
	unsigned long long int X;
	scanf("%lld",&X);
	unsigned long long int number = 100;
	for(unsigned long long int i=1; i<100000000000; i++) {
		number = number * 1.01;
		if(number >= X ){
			printf("%lld",i );
			return 0;
		}
	}
}

