import std.stdio, std.conv, std.string, std.algorithm,
       std.math, std.array, std.container, std.typecons;

long mod = 1000000007;

long modinv(long a) {
  long b=mod, u=1, v=0;
  while(b>0) {
    long t=a/b;
    a -= t*b; swap(a,b);
    u -= t*v; swap(u,v);
  }
  u %= mod;
  if(u<0) u+=mod;
  return u;
}

void main() {
  long x = readln.chomp.to!long;
  long n = 100;
  int count = 0;
  while(n<x) {
    n = n + n/100;
    count++;
  }
  writeln(count);
}
