#include <bits/stdc++.h>
using namespace std;
long long n;
void setup() {
  cin >> n;
  long long ans = 0;
  for (long long val = 1; val <= n; val *= 2) {
    n -= val;
    ans++;
  }
  ans += (n != 0);
  cout << ans;
}
void xuly() {}
int main() {
  iostream::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  setup();
  xuly();
  return 0;
}
