#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#define rep(i,n) for(i=0;i<n;i++)
#define PI 3.14159265358979323846264338327950L
int main(){
    long int x,year=0;
    float dep=100;
    scanf("%ld",&x);
    while(dep<x){
        dep=dep+dep/100;
        year++;
    }
    printf("%d",year);
    return 0;
}