import std.algorithm, std.conv, std.range, std.stdio, std.string; void readV(T...)(ref T t){auto r=readln.splitter;foreach(ref v;t){v=r.front.to!(typeof(v));r.popFront;}} T[] readArray(T)(size_t n){auto a=new T[](n),r=readln.splitter;foreach(ref v;a){v=r.front.to!T;r.popFront;}return a;} T[] readArrayM(T)(size_t n){auto a=new T[](n);foreach(ref v;a)v=readln.chomp.to!T;return a;} const mod = 10^^9+7; alias mint = FactorRing!mod; void main() { int n; readV(n); auto r = mint(1); foreach (i; 1..n*2+1) r *= i; auto inv2 = mint(2).inv; foreach (i; 0..n) r *= inv2; writeln(r); } struct FactorRing(int m, bool pos = false) { version(BigEndian) union { long vl; struct { int vi2; int vi; } } else union { long vl; int vi; } alias FR = FactorRing!(m, pos); @property static init() { return FR(0); } @property int value() { return vi; } @property void value(int v) { vi = mod(v); } alias value this; this(int v) { vi = v; } this(int v, bool runMod) { vi = runMod ? mod(v) : v; } this(long v) { vi = mod(v); } ref auto opAssign(int v) { vi = v; return this; } pure auto mod(int v) const { static if (pos) return v%m; else return (v%m+m)%m; } pure auto mod(long v) const { static if (pos) return cast(int)(v%m); else return cast(int)((v%m+m)%m); } static if (!pos) pure ref auto opUnary(string op: "-")() { return FR(mod(-vi)); } static if (m < int.max / 2) { pure ref auto opBinary(string op)(int r) if (op == "+" || op == "-") { return FR(mod(mixin("vi"~op~"r"))); } ref auto opOpAssign(string op)(int r) if (op == "+" || op == "-") { vi = mod(mixin("vi"~op~"r")); return this; } } else { pure ref auto opBinary(string op)(int r) if (op == "+" || op == "-") { return FR(mod(mixin("vl"~op~"r"))); } ref auto opOpAssign(string op)(int r) if (op == "+" || op == "-") { vi = mod(mixin("vl"~op~"r")); return this; } } pure ref auto opBinary(string op: "*")(int r) { return FR(mod(vl*r)); } ref auto opOpAssign(string op: "*")(int r) { vi = mod(vl*r); return this; } pure ref auto opBinary(string op)(ref FR r) if (op == "+" || op == "-" || op == "*") { return opBinary!op(r.vi); } ref auto opOpAssign(string op)(ref FR r) if (op == "+" || op == "-" || op == "*") { return opOpAssign!op(r.vi); } pure auto opBinary(string op: "/")(FR r) { return FR(mod(vl*r.inv.vi)); } pure auto opBinary(string op: "/")(int r) { return opBinary!op(FR(r)); } ref auto opOpAssign(string op: "/")(ref FR r) { vi = mod(vl*r.inv.vi); return this; } ref auto opOpAssign(string op: "/")(int r) { return opOpAssign!op(FR(r)); } pure auto inv() { int x = vi, a, b; exEuclid(x, m, a, b); return FR(mod(a)); } } pure T exEuclid(T)(T a, T b, ref T x, ref T y) { auto g = a; x = 1; y = 0; if (b) { g = exEuclid(b, a%b, y, x); y -= a/b*x; } return g; }