#include<stdio.h>
#include<math.h>
#include<string.h>
#include<ctype.h>
#include<stdlib.h>
#define STR 1000
int main(){
    long long x=0;
    long cnt=0;
    double money=100;
    scanf("%d",x);
    while(money < x){
        money += money / 100;
        cnt+=1;
    }
    printf("%d",cnt);
    return 0;
}