#include <cstdio>
#include <algorithm>

static const int N = 100;

int n, ans;
int a[N];

int main() {
    freopen("input.txt", "rt", stdin);
    freopen("output.txt", "wt", stdout);

    scanf("%d", &n);

    for (int i = 0; i < n; i++)
        scanf("%d", &a[i]);

    std::sort(a, a + n);

    for (int i = 0; i <= n / 2; i++)
        ans += 1 + a[i] / 2;

    printf("%d", ans);

    return 0;
}