import std.algorithm; import std.array; import std.conv; import std.math; import std.stdio; import std.string; int readint() { return readln.chomp.to!int; } int[] readints() { return readln.split.map!(to!int).array; } void main() { auto na = readints(); int a = na[1]; auto xs = readints(); if (xs.sum / xs.length == a && xs.sum % xs.length == 0) { writeln("YES"); } else { writeln("NO"); } }