import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class Main {
static int n, m;
static int N = 200010;
static int[] head = new int[N];
static int[] e = new int[N];
static int[] nei = new int[N];
static int[] color = new int[N];
static int idx = 0;

public static void build(int x, int y){
    e[idx] = y;
    nei[idx] = head[x];
    head[x] = idx ++;
}

public static boolean dfs(int node, int c){
    color[node] = c;
    for(int i = head[node]; i != -1; i = nei[i]){
        int node_id = e[i];
        if(color[node_id] == 0){
            if(!dfs(node_id, 3 - c))
                return false;
        }
        else if(color[node_id] == c)
            return false;
    }
    return true;
}

public static void main(String[] args) throws IOException {
    BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
    String[] l1 = input.readLine().split(" ");
    n = Integer.parseInt(l1[0]);
    m = Integer.parseInt(l1[1]);

    Arrays.fill(head, -1);

    while(m -- > 0){
        String[] l = input.readLine().split(" ");
        int x = Integer.parseInt(l[0]);
        int y = Integer.parseInt(l[1]);
        build(x, y); build(y, x);
    }


    for(int i = 1; i <= n; i ++){
        if(color[i] == 0){
            if(!dfs(i, 1)){
                System.out.println("No");
                return;
            }
        }
    }
    System.out.println("Yes");
    input.close();
    return;

}

}