#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	stack<int> stk;
	for(int i=1;i<=n;i++) 
	{
		int x;
		cin>>x;
		while(stk.size()&&stk.top()==x)
		{
			x++;
			stk.pop();//删除
			//stk.push(x);
		}
		stk.push(x);
	}
	cout<<stk.size();
	return 0;
}