#include<bits/stdc++.h>

#define    pi          acos(-1) 
#define    all(x)      (x).begin(),(x).end()
#define    fill(x,y)   memset(x, y, sizeof(x))
#define    trace(x)    cout << #x << " = " << x << endl
#define    bug         cout << "Bug check" << endl
#define    endl        '\n'

using namespace std;

int main(){
	//freopen("in.txt","r", stdin);
	//freopen("out.txt","w", stdout);
 
	//ios::sync_with_stdio(0);
	//cin.tie(0);

	int n; cin >> n;

	vector <int> v(n);

	for(int&x : v) cin >> x;

	sort(all(v));

	n = n/2 + 1;

	int s = 0;
	for(int i=0;i<n;i++){
		s+=(v[i]/2)+1;
	}
	cout << s << endl;
	
	return 0;
}