import java.io.*; import java.util.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); int m = sc.nextInt(); UnionFindTree uft = new UnionFindTree(n * 2); for (int i = 0; i < m; i++) { int left = sc.nextInt() - 1; int right = sc.nextInt() - 1; uft.unite(left, right + n); uft.unite(left + n, right); } for (int i = 0; i < n; i++) { if (!uft.same(i, i + n)) { System.out.println("No"); return; } } System.out.println("Yes"); } static class UnionFindTree { int[] parents; public UnionFindTree(int size) { parents = new int[size]; for (int i = 0; i < size; i++) { parents[i] = i; } } public int find(int x) { if (x == parents[x]) { return x; } else { return parents[x] = find(parents[x]); } } public boolean same(int x, int y) { return find(x) == find(y); } public void unite(int x, int y) { if (!same(x, y)) { parents[find(x)] = find(y); } } } } class Utilities { static String arrayToLineString(Object[] arr) { return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n")); } static String arrayToLineString(int[] arr) { return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new)); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public int[] nextIntArray() throws Exception { return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray(); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }