#include<bits/stdc++.h>
using namespace std;

int main(){
	int N;
	cin >> N;
	vector<long long> H(N);
	for(int i=0;i<N;i++) cin >> H[i];
	sort(H.rbegin(),H.rend());
	cout << *ranges::partition_point(views::iota(N,N+61),[&](int x){
		priority_queue<long long> A(H.begin()+max(x-60,0),H.end());
		for(int i=min(x-1,59);i>=0 && !A.empty();i--){
			long long pos=A.top();
			A.pop();
			if(pos>(1LL<<i)) A.push(pos-(1LL<<i));
		}
		return !A.empty();
	}) << '\n';
}