#include <stdio.h>
#include <math.h>

int main (void)
{
    unsigned long cash, x, year;

    scanf("%lu", &x);
    cash = 100;

    for (year=0; cash<x;) {
        cash = (unsigned long)((double)cash * 1.01);
      	year++;
    }

    printf("%lu", year);

    return 0;
}

