#include <bits/stdc++.h>
//#define int long long
#define fi first
#define se second
#define pb push_back
#define ott(i, l, r) for (int i = (l); i <= (r); i ++)
#define tto(i, l, r) for (int i = (r); i >= (l); i --)
int read () {
	int x = 0; bool f = 0; char c = getchar ();
	while (!isdigit (c)) f |= (c == '-'), c = getchar ();
	while (isdigit (c)) x = (x << 3) + (x << 1) + (c ^ 48), c = getchar ();
	if (f) x = -x; return x;
}
using namespace std;
using ll = long long;

const int N = 1e5 + 110, mod = 1e9 + 7, inf = 0x3f3f3f3f;
int n, m, rs, sum, res, now; ll x;
ll f[N << 2];
struct Bag {
	ll v; int w;
} a[N];
int main () {
	n = read (), scanf ("%lld", &x);
	rs = x % 5, x = (x - rs) / 5ll;
	ott (i, 1, n) {
		ll y; scanf ("%lld", &y);
		a[i].w = y % 5, a[i].v = (y - a[i].w) / 5ll;
		if (a[i].w) a[i].w = 5 - a[i].w, ++ a[i].v;
		m += a[i].w;
	}
	memset (f, 0x3f, sizeof f); f[0] = 0;
	if (n <= 3000)
		ott (i, 1, n)
			tto (j, a[i].w, m)
		    	f[j] = min (f[j], f[j - a[i].w] + a[i].v);
	else {
		m = 0;
		ott (i, 1, n) {
			m += a[i].w;
			tto (j, max (a[i].w, m - 2000), m) f[j] = min (f[j], f[j - a[i].w] + a[i].v);
			tto (j, max (a[i].w, m / 2 - 2000), m / 2) f[j] = min (f[j], f[j - a[i].w] + a[i].v);
			tto (j, max (a[i].w, 24000), min (m, 26000)) f[j] = min (f[j], f[j - a[i].w] + a[i].v);
			tto (j, max (a[i].w, 122000), min (m, 126000)) f[j] = min (f[j], f[j - a[i].w] + a[i].v);
		}
	}
	ott (j, 0, m)
		if (f[j] <= x)
		    res = max (res, j);
	printf ("%d\n", sum + res + rs);
    return 0;
}