#include <stdio.h>
#define MIN(x, y) (((x) > (y)) ? (y) : (x))
#define ABS(x) ((x) >= 0 ? (x) : (-(x)))

int main()
{
  long long x;
  scanf("%lld", &x);
  long long sum = 100;
  long long year = 0;
  do {
    sum += sum / 100;
    year++;
  } while (sum < x);
  printf("%lld", year);
  return 0;
}