#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N=2e5+10;
int h[N];
signed main()
{
	int n;scanf("%lld",&n);
	for(int i=1;i<=n;i++)scanf("%lld",&h[i]);
	int t=0;
	for(int i=1;i<=n;i++)
	{
		int k=h[i]/5;
		t+=3*k;h[i]-=5*k;
		if(h[i]==0)continue;
		while(h[i]>0)
		{
			t++;h[i]--;
			if(t%3==0)h[i]-=2;
		}
	}
	printf("%lld\n",t);
	return 0;
}