public void Solve()
{
var n = ri;
var a = Enumerate(n, x => rl);
var mf = new MaxFlow(2 * n + 2);
var src = 2 * n;
var sink = src + 1;
var ans = 0L;
for (int i = 1; i <= n; i++)
{
var v = a[i - 1];
if (v < 0)
{
//???????
mf.AddDirectedEdge(n + i - 1, sink, -v);
}
else
{
ans += v;
//?????
mf.AddDirectedEdge(src, i - 1, v);
}
mf.AddDirectedEdge(i - 1, i + n - 1, INF);
for (int j = 2 * i; j <= n; j += i)
{
// j ??????i ?????????
mf.AddDirectedEdge(j - 1, i - 1 + n, INF);
}
}
var val = mf.Execute(src, sink);
Debug.WriteLine(val);
Console.WriteLine(ans - val);
}
public void Solve()
{
var n = ri;
const int MAX = 10000005;
var a = new int[MAX];
var b = new int[MAX];
foreach (var x in sc.Integer(n))
{
a[x] = 1;
}
for (int i = 0; i < MAX - 1; i++)
{
b[i] = a[i + 1] ^ a[i];
}
var xs = Enumerate(2, x => new List <int>());
for (int i = 0; i < MAX; i++)
{
if (b[i] == 1)
{
xs[i % 2].Add(i);
}
}
var isprime = MathEx.Sieve(10000005);
isprime[2] = false;
var m = xs[0].Count + xs[1].Count;
Debug.WriteLine(m);
Debug.WriteLine(xs[0].AsJoinedString());
Debug.WriteLine(xs[1].AsJoinedString());
var G = new MaxFlow(m + 2);
for (int i = 0; i < xs[0].Count; i++)
{
for (int j = 0; j < xs[1].Count; j++)
{
if (isprime[Math.Abs(xs[0][i] - xs[1][j])])
{
G.AddDirectedEdge(i, xs[0].Count + j, 1);
}
}
}
var f = m;
var t = m + 1;
for (int i = 0; i < xs[0].Count; i++)
{
G.AddDirectedEdge(f, i, 1);
}
for (int i = 0; i < xs[1].Count; i++)
{
G.AddDirectedEdge(xs[0].Count + i, t, 1);
}
var mf = G.Execute(f, t);
var ans = mf;
var u = xs[0].Count - mf;
var v = xs[1].Count - mf;
ans += 2 * (u / 2);
ans += 2 * (v / 2);
if (u % 2 == 1)
{
ans += 3;
}
IO.Printer.Out.WriteLine(ans);
}