// Problem: F - Moniphant Sleep
// Contest: Virtual Judge - 2023年ICPC国际大学生程序设计竞赛全国邀请赛（陕西）
// URL: https://vjudge.net/contest/572825#problem/F
// Memory Limit: 1014 MB
// Time Limit: 3000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
using namespace std;
#define ll long long
# define int long long
#define ull unsigned long long
#define pii pair<int,int>

#define baoliu(x, y) cout << fixed << setprecision(y) << x
#define endl  "\n"
#define debug1(x) cerr<<x<<" "
#define  debug2(x) cerr<<x<<endl
const int N = 2e5 + 10;
const int M = 1e6 + 10;
const int inf = 0x3f3f3f3f;
const int mod = 998244353;
const double eps = 1e-8;
int n, m;
int a[N];

void solve(){
	cin>>n;
	for(int i=1;i<=n;i++)cin>>a[i];
	int ans=0;
	for(int i=1;i<=n;i++)ans+=a[i];
	if(n==1){
		cout<<0;
		return ;
	}
	if(n==2){
		cout<<min(a[1],a[2]);
		return ;
	}
	cout<<ans/2;
}
signed main() {
    cin.tie(0);
    
    ios::sync_with_stdio(false);

    int t;
   //cin>>t;
     t=1;
    while (t--) {
solve();
    }
    return 0;
}