#include <bit>
#include <iostream>

using namespace std;

typedef unsigned long long ull;

// https://stackoverflow.com/a/74374791
int bit_length(ull x) {
    int bits;
    for(bits = 0; x != 0; ++bits) x >>= 1;
    return bits;
}

int main() {
	ull n;
	cin >> n;
	cout << bit_length(n - 1) + 1 << endl;
}