//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
void die(string S){puts(S.c_str());exit(0);}
ll val[1004];
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n;
	ll x;
	cin>>n>>x;
	int ans=x%5;
	x/=5;
	vector<pii> vec;
	while(n--)
	{
		int y;
		cin>>y;
		if(y%5==0) continue;
		vec.pb(y/5+1,5-y%5); 
	}
	sort(ALL(vec),[&](pii a,pii b)
	{
		return 1ll*a.second*b.first>1ll*a.first*b.second;
	});
	int cur=0;
	while(cur<sz(vec)&&vec[cur].first<=x)
	{
		x-=vec[cur].first;
		ans+=vec[cur].second;
	}
	int lim=min(cur,10);
	while(lim--)
	{
		cur--;
		x+=vec[cur].first;
		ans-=vec[cur].second;
	}
	memset(val,0x3f,sizeof(val));
	val[0]=0;
	for(int i=cur;i<sz(vec);i++)
		for(int j=53-vec[i].second;j>=0;j--)
			val[j+vec[i].second]=min(val[j+vec[i].second],val[j]+vec[i].first);
	ll mx=0;
	for(int j=0;j<54;j++)
		if(val[j]<=x)
			mx=j;
	cout<<ans+mx<<endl;
	return 0;
}