import std.conv, std.stdio, std.string; import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex, std.typecons; import core.bitop; class EOFException : Throwable { this() { super("EOF"); } } string[] tokens; string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; } int readInt() { return readToken().to!int; } long readLong() { return readToken().to!long; } real readReal() { return readToken().to!real; } void chmin(T)(ref T t, in T f) { if (t > f) t = f; } void chmax(T)(ref T t, in T f) { if (t < f) t = f; } int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; } int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); } int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); } immutable MO = 1000000007L; immutable LIM = 2 * 10^^5 + 10; long[] inv, fac, invFac; void prepare() { inv = new long[LIM]; fac = new long[LIM]; invFac = new long[LIM]; inv[1] = 1; foreach (i; 2 .. LIM) { inv[i] = MO - (MO / i) * inv[cast(size_t)(MO % i)] % MO; } fac[0] = invFac[0] = 1; foreach (i; 1 .. LIM) { fac[i] = (fac[i - 1] * i) % MO; invFac[i] = (invFac[i - 1] * inv[i]) % MO; } } void add(int[] bit, int pos, int val) { for (int x = pos; x < bit.length; x |= x + 1) { bit[x] += val; } } int getSum(int[] bit, int pos) { int ret; for (int x = pos - 1; x >= 0; x = (x & (x + 1)) - 1) { ret += bit[x]; } return ret; } int N; long K; int[] P; long[] total; long calc(long[] a) { long ret; long num = 0; foreach_reverse (i; 0 .. N) { (ret += total[N - 1 - i] * a[i]) %= MO; (ret += fac[N - 1 - i] * a[i] % MO * (a[i] - 1) % MO * inv[2]) %= MO; (ret += num * a[i]) %= MO; (num += fac[N - 1 - i] * a[i]) %= MO; } return ret; } void main() { prepare(); try { for (; ; ) { N = readInt(); K = readLong(); P = new int[N]; foreach (i; 0 .. N) { P[i] = readInt() - 1; } total = new long[N + 1]; foreach (n; 0 .. N + 1) { total[n] = fac[n] * n % MO * (n - 1) % MO * inv[4] % MO; } auto a = new long[N]; auto bit = new int[N]; foreach (i; 0 .. N) { bit.add(i, +1); } foreach (i; 0 .. N) { a[i] = bit.getSum(P[i]); bit.add(P[i], -1); } debug { writeln("a = ", a); } long ans; ans -= calc(a); a[N - 1] += K; foreach_reverse (i; 1 .. N) { a[i - 1] += a[i] / (N - i); a[i] %= (N - i); } const b = a[0] / N; a[0] %= N; debug { writeln("a = ", a); writeln("b = ", b); } ans += calc(a); ans += total[N] * (b % MO); ans = (ans % MO + MO) % MO; writeln(ans); } } catch (EOFException e) { } }