public void Solve()
{
int N = Reader.Int();
var table = Reader.IntTable(N);
int MaxVal = table.Max(t => Math.Max(t[0], t[1]));
var dp = new int[MaxVal * 2 + 2, MaxVal * 2 + 2];
foreach (var t in table)
{
dp[MaxVal - t[0], MaxVal - t[1]]++;
}
for (int a = 0; a <= MaxVal * 2; a++)
{
for (int b = 0; b <= MaxVal * 2; b++)
{
Add(ref dp[a + 1, b], dp[a, b]);
Add(ref dp[a, b + 1], dp[a, b]);
}
}
var C = new ModC(MaxVal * 4, Mod);
long ans = 0;
foreach (var t in table)
{
ans += dp[t[0] + MaxVal, t[1] + MaxVal];
ans -= C[(t[0] + t[1]) * 2, t[0] * 2];
}
ans = (ans % Mod * ModPower(2, Mod - 2, Mod) % Mod + Mod) % Mod;
Console.WriteLine(ans);
}
public void Solve()
{
int A = Reader.Int(), B = Reader.Int(), C = Reader.Int();
if (B > C)
{
int t = B; B = C; C = t;
}
long ans = 0;
var Comb = new ModC(A + B + C, Mod);
long BCcomb = 1;
for (int S = A - 1; S <= A - 1 + B + C; S++)
{
long count = Comb[S, A - 1];
ans = (ans + count * BCcomb % Mod * ModPower(3, A + B + C - S - 1, Mod)) % Mod;
BCcomb = BCcomb * 2 % Mod;
int rem = S - A + 1;
if (rem >= B)
{
BCcomb = (BCcomb + Mod - Comb[rem, B]) % Mod;
}
if (rem >= C)
{
BCcomb = (BCcomb + Mod - Comb[rem, rem - C]) % Mod;
}
}
Console.WriteLine(ans);
}
public void Solve()
{
int H = Reader.Int(), W = Reader.Int(), A = Reader.Int(), B = Reader.Int();
var C = new ModC(H + W, Mod);
int ans = 0;
long last = 0;
for (int x = B; x < W; x++)
{
int h1 = H - A - 1;
int w1 = x;
int h2 = A;
int w2 = W - x - 1;
long a = C[h1 + w1, w1], b = C[h2 + w2, w2];
if (last > 0)
{
a = a + Mod - last;
}
last = C[h1 + w1, w1];
Add(ref ans, (int)(a * b % Mod));
}
Console.WriteLine(ans);
}
public void Solve()
{
int A = Reader.Int(), B = Reader.Int(), C = Reader.Int();
if (B > C)
{
int t = B; B = C; C = t;
}
long ans = 0;
var Comb = new ModC(A + B + C, Mod);
var pow3 = new long[A + B + C];
pow3[0] = 1;
for (int i = 1; i < pow3.Length; i++)
{
pow3[i] = pow3[i - 1] * 3 % Mod;
}
long BCcomb = 1;
for (int S = A - 1; S <= A - 1 + B + C; S++)
{
ans = (ans + Comb[S, A - 1] * BCcomb % Mod * pow3[A + B + C - S - 1]) % Mod;
BCcomb = BCcomb * 2 % Mod;
int rem = S - A + 1;
if (rem >= B)
{
BCcomb = (BCcomb + Mod - Comb[rem, B]) % Mod;
}
if (rem >= C)
{
BCcomb = (BCcomb + Mod - Comb[rem, rem - C]) % Mod;
}
}
Console.WriteLine(ans);
}
public void Solve()
{
int N = Reader.Int(), X = Reader.Int(), Y = Reader.Int();
var dic = new Dictionary <int, List <int> >();
int[] C = new int[N], W = new int[N];
for (int i = 0; i < N; i++)
{
C[i] = Reader.Int(); W[i] = Reader.Int();
AddDic(dic, C[i], i);
}
if (dic.Count == 1)
{
Console.WriteLine(1); return;
}
var mins = new List <int>();
var uf = new UnionFind(N);
foreach (var A in dic.Values)
{
int minW = int.MaxValue, who = 0;
foreach (int i in A)
{
if (CheckMin(ref minW, W[i]))
{
who = i;
}
}
mins.Add(who);
foreach (int i in A)
{
if (minW + W[i] <= X)
{
uf.Unite(who, i);
}
}
}
mins = mins.OrderBy(i => W[i]).ToList();
foreach (var A in dic.Values)
{
for (int mi = 0; mi < 2; mi++)
{
if (C[mins[mi]] != C[A[0]])
{
foreach (int i in A)
{
if (W[mins[mi]] + W[i] <= Y)
{
uf.Unite(mins[mi], i);
}
}
}
}
}
long ans = 1;
modC = new ModC(N, Mod);
foreach (var A in uf.Components().Values)
{
var count = new Dictionary <int, List <int> >();
foreach (int i in A)
{
AddDic(count, C[i], 1);
}
ans *= Count(count.Values.Select(v => v.Count).ToArray());
ans %= Mod;
}
Console.WriteLine(ans);
}
