#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
const int N = 100010, M = 2 * N;
int e[M], ne[M], h[N], idx;
int color[N];
int n, m;
void add(int a, int b)
{
e[idx] = b, ne[idx] = h[a], h[a] = idx++;
}
bool dfs(int u, int a)
{
color[u] = a;
for(int i = h[u]; i != -1; i = ne[i])
{
int j = e[i];
if(!color[j])
{
if(!dfs(j, 3 - a)) return false;
}
else if(color[j] == a) return false;
}
return true;
}
int main()
{
cin >> n >> m;
memset(h, -1, sizeof h);
int a, b;
for(int i = 0; i < m; i++)
{
scanf("%d%d", &a, &b);
add(a, b);
add(b, a);
}
bool flag = true;
for(int i = 1; i <= n; i++)
{
if(!color[i])
{
if(!dfs(i, 1))
{
flag = false;
break;
}
}
}
if(flag) cout << "Yes";
else cout << "No";
return 0;
}