#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<math.h>
int main()
{
    long long int x,i;
    scanf("%lld",&x);
    long long int ans;
    long long int principle=100;
    long long int compounded;
    for(i=1;;i++)
    {
        compounded=(principle+(principle/100));
        principle=compounded;
        ans=compounded;
        if(ans>=x)
        break;
    }
    printf("%lld",i);
}