/* -*- coding: utf-8 -*-
 *
 * 2664.cc:  No.2664 Prime Sum - yukicoder
 */

#include<cstdio>
#include<vector>
#include<queue>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 100;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;

/* global variables */

vi nbrs[MAX_N];
int ds[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, m;
  scanf("%d%d", &n, &m);

  for (int i = 0; i < m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    u--, v--;
    nbrs[u].push_back(v);
    nbrs[v].push_back(u);
  }

  fill(ds, ds + n, -1);

  for (int st = 0; st < n; st++)
    if (ds[st] < 0) {
      ds[st] = 0;
      qi q;
      q.push(st);

      while (! q.empty()) {
	int u = q.front(); q.pop();
	for (auto v: nbrs[u]) {
	  if (ds[v] < 0) {
	    ds[v] = ds[u] ^ 1;
	    q.push(v);
	  }
	  else if (ds[v] == ds[u]) {
	    puts("No");
	    return 0;
	  }
	}
      }
    }

  puts("Yes");
  return 0;
}