#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;

int main()
{
    int N, M;
    cin >> N >> M;
    vector<int> p(N, -1);
    for (int i = 0; i < M; i++)
    {
        int A, B;
        cin >> A >> B;
        A--;
        B--;
        if (p[A] == -1 && p[B] == -1)
        {
            p[A] = 0;
            p[B] = 1;
        }
        else if (p[A] == -1)
        {
            p[A] = p[B] ^ 1;
        }
        else if (p[B] == -1)
        {
            p[B] = p[A] ^ 1;
        }
        else if (p[A] == p[B])
        {
            cout << "No";
            return 0;
        }
    }
    cout << "Yes";
}