// yukicoder: No.549 素材合成システム
// 2019.7.9 bal4u

#include <stdio.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif

int in() {   // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

int main()
{
	int ma, x, N, ans;
	
	ans = ma = 0, N = in();
	while (N--) {
		x = in();
		if (x > ma) ma = x;
		ans += x >> 1;
	}
	ans += ma - (ma >> 1);
	printf("%d\n", ans);
	return 0;
}