import java.io.*;
import java.util.Arrays;

class Main {

    //稀疏图，邻接表
    static int n, m, idx;
    static int[] h = new int[100010];
    static int[] e = new int[200010];
    static int[] ne = new int[200010];

    static {
        Arrays.fill(h, -1);
    }

    //记录点属于的集合
    //1:左半部; 2:右半部
    static int[] ce = new int[100010];

    //bfs队列
    static int[] queue = new int[100010];
    static int head, tail;

    static void insert(int a, int b) {
        e[idx] = b;
        ne[idx] = h[a];
        h[a] = idx++;
    }

    static boolean bfs(int a, int c) {
        queue[tail++] = a;
        ce[a] = c;
        while (head < tail) {
            int t = queue[head++];
            int color = ce[t];
            for (int i = h[t]; i != -1; i = ne[i]) {
                int next = e[i];
                if (ce[next] == 0) {
                    ce[next] = 3 - color;
                    queue[tail++] = next;
                } else if (ce[next] == 3 - color) continue;
                else return false;
            }
        }
        return true;
    }

    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader in = new BufferedReader(isr);
        String[] strs = in.readLine().split(" ");
        n = Integer.parseInt(strs[0]);
        m = Integer.parseInt(strs[1]);
        for (int i = 1; i <= m; i++) {
            strs = in.readLine().split(" ");
            int a = Integer.parseInt(strs[0]);
            int b = Integer.parseInt(strs[1]);
            insert(a, b);
            insert(b, a);
        }

        in.close();
        isr.close();

        OutputStreamWriter osw = new OutputStreamWriter(System.out);
        BufferedWriter out = new BufferedWriter(osw);

        //遍历所有连通块
        boolean flag = true;
        for (int i = 1; i <= n; i++) {
            if (ce[i] == 0 && !bfs(i, 1)) {
                flag = false;
                break;
            }
        }

        if (flag) out.write("Yes");
        else out.write("No");

        out.flush();
        out.close();
        osw.close();
    }
}