import core.bitop; import std.algorithm; import std.array; import std.ascii; import std.container; import std.conv; import std.format; import std.math; import std.range; import std.stdio; import std.string; import std.typecons; void main() { auto v = readln.chomp.split.map!(to!int); int n = v.front; int m = v.back; int[] adj = new int[](n); foreach (i; 0..m) { auto s = readln.chomp.split.map!(to!int); int a = s.front; int b = s.back; adj[a]++; adj[b]++; } auto cnt = adj.filter!(a => a % 2 == 1).count; auto ans = cnt == 2; enum R = ["NO", "YES"]; R[ans].writeln; }